Resistance to Elevated Temperature

This investigation aims to present a new approach to study the effect of using polymer latex on the performance of latex cement co-matrix strength. This study was carried out to investigate the effect of latex addition with styrene butadiene rubber as chemical base on cement matrix participation ratio in strength of modified cement paste. Degree of hydration, and compressive strength were measured to evaluate the effect of latex addition on cement participation ratio in latex modified co-matrix strength. According to the new approach, latex network has a great participation ratio in co-matrix strength. The second stage in this study shows an attempt to evaluate the latex participation ratio in mortar and concrete strength with different latex chemical bases. The new approach considers the latex with chemical base of acrylic ester, and polyvinyl acetate has similar effect of styrene butadiene rubber. Effect of latex particles size on latex network strength was studied using the new approach. The test results indicated that the latex participation ratio in co-matrix strength is influenced by type of cement matrix, type of curing, latex type, latex solid/water ratio, strength type and age. For modified concrete, when the SBR solid/water ratio increases the latex participation ratios in flexural and pull out bond strength increases. Generally, the latex participation ratio in co-matrix strength decreases as latex particle size increases.

The effectiveness of powdered emulsions (powdered cement modifiers) and aqueous polymer dispersions (aqueous cement modifiers) on improvements in strength and elastic properties of mortars is investigated in this paper. Polymer-modified mortars using various powdered and aqueous cement modifiers were prepared with variation in polymer-cement ratio, and tested for flexural strength, compressive strength, tensile strength, deflection, extreme tensile fiber strain and tensile strain. It is concluded from the test results that powdered cement modifiers affect the properties of mortars similarly as the aqueous cement modifiers and the powdered polymer-modified mortars can be used in the same manner as the aqueous polymer-modified mortars for practical applications. 1200 M.U.IC Afridi et al. Vol. 24, No. 7 Materials Cement and Fine Aggregate Ordinary portland cement and Toyoura standard sand as specified in JIS (Japanese Industrial Standard) were used in all mixes. Commercially available, four powdered and two aqueous cement modifiers were used. The powdered cement modifiers used included one brand of poly (vinyl acetate-vinyl carboxylate) (VA/VeoVa) type and three brands of poly (ethylene-vinyl acetate), (EVA) type. The aqueous cement modifiers used were one brand of EVA emulsion and one brand of styrene-butadiene rubber (SBR) latex type. Their typical properties are given in Table . Before mixing, a silicone emulsion type antifoamer containing 30% silicone solids was added to the cement modifiers in a ratio of 0.7% of the silicone solids in the antifoamer to the total solids in the powdered and aqueous cement modifiers.

High volume fly ash concrete (HVFAC) is a concrete in which the cement is replaced by fly ash by 50% or more than 50%. Textile reinforced concrete (TRC) is a form of concrete, where conventional reinforcement is replaced with textile fibers. Because of the high tenacity ofthe concrete prepared by textile fibers will result in flexible and durability of structures.The characteristics of workability and compressive strength of polymer modified high volume fly ash concrete (PMHVFAC) with different mono textile fibers and hybrid textile fibers are investigated in this paper. In the present study the textile fibers such as carbon fiber, polypropylene fiber, nylon fiber, polyster fiber and polyethelene fiber are used. The results depicts that,there is adrastic reduction of workability in PMHVFAC produced from hybrid textile fibers and mono textile fibers. In addition, the compressive strength of PMHVFAC produced with different hybrid textile fibers are more as compared to HVFAC and their respective mono textile fib

In this research, the effect of elevated temperature on the flexural behavior of one-way reinforced concrete slabs under service static loads contain different volume fraction (0.25% , 0.75% and 1.25%) of steel fibers and different addition ratios (15%, 20% and 25%) of fly ash in addition to the reference slabs with not any additives was studied. For this purpose, thirty cylinders (150 *300)mm , thirty prisms (100 * 100 * 500)mm and forty one-way slabs (900 * 350 * 70) mm were cast and tested. The one-way tested slabs were divided into two groups. The first group (of twenty slabs) were tested to determine the ultimate flexural strength under static loads at normal temperature. While the second group (of twenty slabs) were tested to determine the flexural behavior of slabs under static service loads at elevated temperature (using burning furnace). In this test, the samples are exposed to rising temperature reached 850℃. From these tests, the relationships between the load and mid-span deflection as well as the relations between the fire-time and mid-span deflection are measured. The results showed that the addition of steel fibers and fly ash particles will enhance the flexural behavior of concrete slabs. The highest increase in ultimate load compared to the reference slab was (28.31%) at the volume ratio 1.25% of the steel fibers and 25% of the fly ash at normal temperatures , And the rate of increase of the deflection with fire time was the lowest increase rate is 14.1% at the volume of 1.25% of steel fibers and the proportion of weight 20% of fly ash at high temperature.

Over the years, the world has tried to increase the recycling of materials, especially those of artificial origin, this in order to produce compounds that are sustainable and sustainable. Among these materials, concrete stands out as a versatile element, to which different external agents can be added; however, since many of them are not compatible with aggregates, cement or water, can cause some alterations in their mechanical performance. Therefore, the present investigation addressed the study of an artificial material called Microporous Ethylene Vinyl Acetate (MEVA), in order to evaluate its influence on the mechanical properties of structural concrete. MEVA additions were used in ranges of 5.00 %, 10.00 %, 15.00 % and 20.00 % with respect to the volume of concrete, to analyze its behavior in the mix, both in physical and mechanical properties. The results show that the workability and unit weight are affected by the increase in MEVA. Despite this, the mechanical performance showed significant increases in the compressive strength of 8.81 %, tensile of 22.86 %, flexion of 24.51 % and modulus of elasticity of 2.12 %, with the addition of 5.00 % of MEVA after 28 days. Nevertheless, at higher doses there is a reduction in said strengths. For these reasons, it is concluded that the incorporation of MEVA at 5.00 % greatly improves the mechanical properties of concrete for structural use, in relation to the theoretical design strength of 21.00 MPa.

Cement mortar linings are often specified for the internal corrosion protection of steel pipelines conveying potable water. One of the limitations of cement mortar lining is that it can crack and debond from the steel pipe wall. An investigation into the effects of temperature, curing and pipe handling upon the cracking of factory spray applied and rotary steel trowelled mortar lining is described. Four 19.2-m long 1400-mm diameter steel pipes were instrumented and monitored prior to lining through to the end of the curing phase and two pipes were monitored during loading, transportation and delivery at the pipeline trench.

In this experimental study, a mechanical and economic analysis has been done to investigate the performance of recycled steel fibers (RSF) from waste tires. Two types of recycled fibers, including Recycled Steel Fibers with Impurities (with a high amount of rubber and textiles) (RSFI) and Clean Recycled Steel Fibers (CRSF), have been investigated. Recycled fiber's performance has been compared to Industrial Steel Fibers (ISF); these fibers have hook ends. The mechanical properties of normal concrete and concrete reinforced with steel fibers, including compressive strength, splitting tensile strength, and flexural strength, were investigated at ambient temperature and temperatures of 200 °C and 600 °C. The results showed that at ambient temperature and 200 ℃, RSFI decreases the compressive strength of concrete due to the high amount of rubber and textiles, while CRSF has shown results comparable to ISF at all temperatures. The positive effect of RSFI has been observed at 600 ℃ by melting rubber and burning textiles. The specimens reinforced with steel fibers, regardless of their type, improved the tensile strength and modulus of rupture compared to the control specimen at all temperatures. RSFI has shown poorer performance compared to ISF and CRSF. The mechanical and economic analysis showed that CRSF could be a suitable alternative to ISF to strengthen concrete mixtures.

The percentage of concrete porosity will affects the strength and performance of the concrete. It is believed that, with an additional curing, the porosity of the concrete becomes lower and the strength will increase. This paper presents a relationship between the strength development and porosity of epoxy-modified mortar. Epoxy-modified mortar is a type of polymer-modified which uses an epoxy resin without hardener as an addition material. Mortar specimens were prepared with a mass ratio of 1:3 (cement: fine aggregates), water-cement ratio of 0.48 and epoxy content of 5, 10, 15 and 20% of cement. The specimens were subjected to dry and wet-dry curing and the tests conducted were workability, setting time, compressive strength, flexural strength, tensile splitting strength, porosity and strength development. Results show that workability and setting time of the mortar decreased as epoxy content increased. Compressive, flexural and tensile splitting strengths of epoxy-modified mortar with wet-dry curing were significantly higher and became constant at 10% of epoxy resin content. A significant improvement in strength development of mortar without hardener was achieved even after 365 days of curing. The porosity of the mortar decreased as strength development increased. This was due to the gradual hardening reaction of epoxy resin with cement hydrates that filled the void inside; hence produced a denser and stronger mortar.

This investigation aims to present a new approach to study the effect of using polymer latex on the performance of latex cement co-matrix strength. This study was carried out to investigate the effect of latex addition with styrene butadiene rubber as chemical base on cement matrix participation ratio in strength of modified cement paste. Degree of hydration, and compressive strength were measured to evaluate the effect of latex addition on cement participation ratio in latex modified co-matrix strength. According to the new approach, latex network has a great participation ratio in co-matrix strength. The second stage in this study shows an attempt to evaluate the latex participation ratio in mortar and concrete strength with different latex chemical bases. The new approach considers the latex with chemical base of acrylic ester, and polyvinyl acetate has similar effect of styrene butadiene rubber. Effect of latex particles size on latex network strength was studied using the new approach. The test results indicated that the latex participation ratio in co-matrix strength is influenced by type of cement matrix, type of curing, latex type, latex solid/water ratio, strength type and age. For modified concrete, when the SBR solid/water ratio increases the latex participation ratios in flexural and pull out bond strength increases. Generally, the latex participation ratio in co-matrix strength decreases as latex particle size increases.

This investigation aims to present a new approach to study the effect of using polymer latex on the performance of latex cement co-matrix strength. This study was carried out to investigate the effect of latex addition with styrene butadiene rubber as chemical base on cement matrix participation ratio in strength of modified cement paste. Degree of hydration, and compressive strength were measured to evaluate the effect of latex addition on cement participation ratio in latex modified co-matrix strength. According to the new approach, latex network has a great participation ratio in co-matrix strength. The second stage in this study shows an attempt to evaluate the latex participation ratio in mortar and concrete strength with different latex chemical bases. The new approach considers the latex with chemical base of acrylic ester, and polyvinyl acetate has similar effect of styrene butadiene rubber. Effect of latex particles size on latex network strength was studied using the new approach. The test results indicated that the latex participation ratio in co-matrix strength is influenced by type of cement matrix, type of curing, latex type, latex solid/water ratio, strength type and age. For modified concrete, when the SBR solid/water ratio increases the latex participation ratios in flexural and pull out bond strength increases. Generally, the latex participation ratio in co-matrix strength decreases as latex particle size increases.

NUTC R345 Disclaimer The contents of this report reflect the views of the author(s), who are responsible for the facts and the accuracy of information presented herein. This document is disseminated under the sponsorship of The goal of the proposed work is to investigate the application of nano-engineered polyurethane (NEPU) emulsions for latex modified concrete (LMC). NEPU emulsions are non-toxic, environment friendly, durable over a wide temperature range, provide better adhesion, high strength, less cracking, and compatible with all mortar types. One of the weak links in a cement-aggregate composite material is the bond between the matrix and the aggregates. To improve the performance of the alternative cement binder (ACB), the research team intends to develop a NEPU resin to act as an intermediary between the aggregates and the ACB matrix. The NEPU will be used to precoat the aggregates prior to their placement within the ACB matrix. When combined with the ACB and water, the unh...

The primary objective of this experimental study is to examine the response and energy absorption capacity of ferrocement panels exposed to low-and high-velocity impact loads. The panels are reinforced with two different types of mesh layers, namely, welded wire grid (WWG) and expanded wire grid (EWG), with varying percentages of steel fibers (SF). The ferrocement panel system is made up of cement mortar reinforced with 0−2% SF with an increment of 1% and wire grid layers arranged in three different layers 1, 2, and 3. A consistent water−cement ratio (w/c) of 0.4 is maintained during mortar preparation, and all panels are subjected to a 28-day curing process in water. The study utilized square-shaped ferrocement panels measuring 290 mm × 290 mm × 50 mm. The panels are exposed to repeated impact blows from a 2.5 kg falling mass dropped from a height of 0.80 m. The count of blows necessary to commence the first crack formation and the cause of ultimate failure are recorded for each panel. The study reports that an increase in SF content and the number of wire grid layers increased the number of blows needed for both the first crack and the ultimate failure. In the high-velocity impact test, 7.62 mm bullets are fired at the panels from a distance of 10 m with a striking velocity of 715 m/s. The study observed and analyzed the extent of spalling, scabbing, and perforation. The results showed that an increase in fiber content and the number of wire grid layers led to a decrease in the area of scabbing and spalling compared with the control specimens. It was also possible to see the mode of failure and crack pattern for impacts with low and high velocities.

This work presents an experimental study on both short-term and long-term deflections for a period more than seven months of reinforced high and normal strength reinforced concrete two-way flat plate panels. Four reinforced concrete panels with dimensions of (960×960×50) mm were investigated with simply supported edges. Concrete cube strength is about 75 MPa for HSC panels, and 30 MPa for the control panel. Sustain load kept along the entire test period and at the end, the loads is removed and the recoverable deflection was measured. It's been concluded that the rate of increase in HSC panels' long time deflection is less than that of NSC panels, also the longterm deflection is highly reduced by increasing the compressive strength of concrete and the long term deflection reduced about 20% when compressive strength increased from 25 to 65 MPa.

Experimental research was conducted to investigate the structural behavior of concrete-encased composite beams. Specimens were tested under lateral loading. The test results indicate that the behavior and failure mode of the beam are greatly affected by the steel beam core. The beams showed highly ductile behavior. The design flexural strength of concrete-encased beams is calculated from both the elastic and plastic stress distribution on the composite section. The deflection at the mid-span of the beam cannot be well predicted using linear elastic theory.

The products of the demolished concrete from the effects of bombing and the spread of waste plastic bottles everywhere are among the largest pollutants that threaten the environment, especially in Iraq after the wars it passed and the weak basic services. In this study, demolished concrete products were used after being crushed and replaced with coarse aggregate and the addition of fibers produced from manual chopping of plastic bottles used in preserving soft drinks to improve the impact property and some mechanical properties of concrete. Two mixtures were poured, the first containing coarse aggregate with different fibers ratios, and the second coarse aggregate was replaced by crushed concrete products with different fibers ratios. Also, two reference mixtures were poured without adding fibers to each type for the purpose of comparison. The results of concrete containing natural coarse aggregate at the percentage of adding fibers (1.2%) Showed a slight decrease in concrete density by (3.56%) And an improvement in compression resistance and bending resistance by (17.4%) (44.82%) At age (28) days, respectively, and improvement in the impact resistance of slabs by (285.71%) At age (56) days. The results of concrete containing recycled aggregates of damaged concrete at the percentage of adding fibers (1.2%) Showed a slight decrease in the density of concrete by (3.08%) And an improvement in compression resistance and bending resistance by (28.1%) (42.26%) At age (28) days respectively, the impact resistance of the slabs improved by (320%) At age (56) days.

Corrosion is one of the major durability problems that causes serious damage to reinforced concrete slabs in harsh environments. The flexural behavior of concrete slabs subjected to corrosive effects during mixing and/or curing is experimentally investigated in this paper. The harsh environments are simulated by subjecting concrete slabs to different Hydrochloric Acid (HCl) concentrations in deionized water during mixing and/or curing. The effect of adding Calcium Carbonate (CaCo3) as nano-material to mitigate the corrosion problem in concrete slabs is examined. Thirty-one simply supported slabs subjected to corrosive environment are experimentally tested in flexure. One slab is used as reference specimen, while thirty slabs are divided into three groups according to corrosion acceleration periods (one month or three months). In the experimental program, the primary variables are corrosion time, concentrations of the HCl solution in mixing or curing water as well as concentrations o...

The purpose of this study is to research both the performance of the reinforced concrete beams without fiber and the performance of the reinforced concrete beams with fiber. For this purpose, the experimental load - displacement curves of beams were formed and the areas under these curves were compared. According to the results of this comparison, it is concluded that the reinforced concrete beams with polypropylene fiber are more ductile. The dimension of the used beam-samples for test in this study is 20x30 cm, their length is 200 cm and their scale is ½. The reinforced concrete reference-beams are produced as two items and the reinforced concrete beams with P-0.60 kg/m polypropylene fiber are produced as three items

One of the new concrete technology applications that had to get increased importance as repairing and retrofitting technique is slurry infiltrated fiber concrete (SIFCON). This research aims to investigate some of the mechanical properties of SIFCON and its role in improving the useful life of normal concrete. The research consists of two parts; in the first part, three mixes are prepared with 0%, 1.5%, and 6% volume fraction steel fiber content. Compressive strength, flexural strength, total absorption and apparent density tests are made for each mix. In the second part, a composite section of normal concrete and SIFCON mix with 6% steel fiber is prepared. Different thicknesses of SIFCON layer had been casted to assess its benefits in repair and/or to strengthen of defected buildings. Flexural strength, toughness, ductility and load-deflection curve are examined for the composite sections. The results showed that the flexural strength of SIFCON with 6% steel fiber content increased up to 600% and 200% compering to those recorded with the reference mix and 1.5% steel fiber concrete respectively. The results also indicated that the increase of SIFCON layer thickness would improve the mechanical properties of the composite section. Also, the maximum increase in flexural strength was greater than four times the reference mix. Better behavior is also recorded in load deflection and toughness of SIFCON composite section.

One of the new concrete technology applications that had to get increased importance as repairing and retrofitting technique is slurry infiltrated fiber concrete (SIFCON). This research aims to investigate some of the mechanical properties of SIFCON and its role in improving the useful life of normal concrete. The research consists of two parts; in the first part, three mixes are prepared with 0%, 1.5%, and 6% volume fraction steel fiber content. Compressive strength, flexural strength, total absorption and apparent density tests are made for each mix. In the second part, a composite section of normal concrete and SIFCON mix with 6% steel fiber is prepared. Different thicknesses of SIFCON layer had been casted to assess its benefits in repair and/or to strengthen of defected buildings. Flexural strength, toughness, ductility and load-deflection curve are examined for the composite sections. The results showed that the flexural strength of SIFCON with 6% steel fiber content increased up to 600% and 200% compering to those recorded with the reference mix and 1.5% steel fiber concrete respectively. The results also indicated that the increase of SIFCON layer thickness would improve the mechanical properties of the composite section. Also, the maximum increase in flexural strength was greater than four times the reference mix. Better behavior is also recorded in load deflection and toughness of SIFCON composite section.

Nylon fibers are used as strengthening material to increase the mechanical properties of concrete.In thisstudy mechanical properties of concrete containing latex modified nylon fiber reinforced concrete wasassessed with fractional substitution of cement by flyash for M40 grade concrete at 7 days, 14 days and 28days of curing. The dosage of fibres used in this study was 0.05%, 0.1% and 0.15% of volume fraction.Cement was replaced with fly ash at a percentage of 10%, 15%, 20% by weight. SBR latex was varied at arate of 0.05%, 0.1%, 0.15% to the total cementitious content in concrete. Cube, cylinder and prism specimensare tested to determine the compressive, split tensile and flexural strength at 7 days and 28 days curing.Results shows that Nylon fiber reinforced concrete with 0.15% of fiber, 0.05% SBR Latex with 10% hashigher influence on flexural strength, split tensile strength and compressive strength of concrete.

The study is conducted to perform two goals: The first geal is to produce a lightweight concrete using major components which are locally available with some standard admixtures.Many mixtures are prepared using many ratios of superplasticizer (SP) and silica fume (SF) admixtures to yield a lightweight aggregate concrete, the effects of using different ratios of these admixtures on unit weight, compressive strength and flexural strength are studied individually and accumulatively. The secondis to study the dynamic specifications of normal and lightweight reinforced concrete beams. The results showed that the increasing in dosage of superplasticizer (SP) for (LWAC) increases the density of (LWAC), and the increasing in dosage of silica fume (SF) decreases the density of (LWAC). The experimental impact tests for R.C. beams shows that the lightweight R.C. beams have a better response under impact loading with respect to the maximum dynamic deflection (2.955mm for normal weight beam and 1.58mm for lightweight beam). Also,Impact force transferred to supports reactions of lightweight beams is smaller within 45% than the impact force transferred to reaction of normal weight concrete under the same impact load, and the time to reach 90% damping equal to 1.223 sec and 1.6 sec for lightweight and normalweight R.C. beams respectively. Also, the reinforced concrete beams are tested under repeated impact load up to failure. The tests showed that the no. of blows to cause first crack for lightweight concrete beams more than twice of this for normalweight concrete beams.

Since the starting the 21st century, there is an increased awareness that nonrenewable resources are becoming scarce, and dependence on renewable resources is growing. The 21st century may be the cellulosic century as we look more and more to renewable plant resources for products. It is easy to say that natural fibers are renewable and sustainable. Although the use of these materials is not new, horse hair was used in mortar and straw for mud bricks, and many plants types like sisal, coir, bamboo, jute, akwara, elephant grass…etc. In this papers, a human hair fibers (HHF) is studied as a reinforced material in cementitious material. A total of 86 concrete specimens (Cubes, cylinders, prisms and plates) are tested to study the effect of including human hair fibers HHF reinforcement on the mechanical properties of flowable mortar fiber reinforced concrete. Fibers of different lengths and equivalent diameters were used with an aspect ratio ranged from 500 to 700, fiber content ranges from zero to 1 percent by volume. The influence of fiber content on the compressive strength, splitting tensile strength, flexural strength and load deflection is presented for two w/c ratios (0.6 and 0.7). An improvement in the energy absorption capacity due to the fiber addition is observed, and the optimum fiber volume fracture is seen to be 0.8%. The experimental findings in our tested samples will encourage future researches in this direction for long term performance to extending this cheap type of fibers for use in structural applications especially for low strength cementitious materials.

Polymers are considered one of the admixture kinds which they are used to improve the quality and the performance of mortar and concrete. In this study the Styrene Butadiene Rubber (SBR) was used as a polymer to see its effects on the mortar. The (SBR) is considered as a water resistance polymer and bonding agent. Four cement mortar mixes were made in this study, the first one was considered as a reference mix which is not include (SBR) while the other mixes were included (SBR) in deferent percentages. The (SBR) was added as a percentage of cement weight. The amount of mixing water was varied to achieve the same flow which was accomplished in the reference mix throughout carrying out flow table test. Flow table test was adopted according to ASTM C 1439-99 (1) recommendations. For each mix, two prisms were prepared to carry out the drying shrinkage test, nine cubes for the compressive strength test and three cubes for the total water absorption test. It was found that when the quantity of (SBR) increases, the physical properties of mortar under study (drying shrinkage, compressive strength and total water absorption) deteriorate which is adverse to the proposal of advantages due to adding (SBR). This result leads to that the recommendation of ASTM C 1439-99 (1) that adopt the flow table as criteria of adjusting the amount of adding water accompanying with deferent percentages of (SBR) is not adequate.

This investigation aims to present a new approach to study the effect of using polymer latex on the performance of latex cement co-matrix strength. This study was carried out to investigate the effect of latex addition with styrene butadiene rubber as chemical base on cement matrix participation ratio in strength of modified cement paste. Degree of hydration, and compressive strength were measured to evaluate the effect of latex addition on cement participation ratio in latex modified co-matrix strength. According to the new approach, latex network has a great participation ratio in co-matrix strength. The second stage in this study shows an attempt to evaluate the latex participation ratio in mortar and concrete strength with different latex chemical bases. The new approach considers the latex with chemical base of acrylic ester, and polyvinyl acetate has similar effect of styrene butadiene rubber. Effect of latex particles size on latex network strength was studied using the new approach. The test results indicated that the latex participation ratio in co-matrix strength is influenced by type of cement matrix, type of curing, latex type, latex solid/water ratio, strength type and age. For modified concrete, when the SBR solid/water ratio increases the latex participation ratios in flexural and pull out bond strength increases. Generally, the latex participation ratio in co-matrix strength decreases as latex particle size increases.

To study the residual strength of concrete beams made from a new type of scoria aggregate after being exposed to fire, six concrete beams were tested, including three normal aggregate concrete (NAC) beams and three scoria aggregate concrete (SAC) beams. First, the beams were exposed to fire for 60 min (2 beams) and 90 min (2 beams) and then subjected to four-point bending tests. The effect of the duration of fire exposure on the load-midspan deflection relationship and the beam failure modes was evaluated with an advanced digital image correlation (DIC) camera. The experimental results indicate that at certain locations, the temperature of the SAC beams after 60 min and 90 min of fire exposure was lower than that of the NAC beams. When the duration of fire exposure was 90 min, the ultimate load capacity of the SAC beams decreased by approximately 11% compared with the ultimate load capacity of the beams at ambient temperature, and the ultimate load capacity of the NAC beams decreased by approximately 17.5% under the same conditions. After a fire, the internal bonds of concrete are damaged, and this damage manifests as concrete spalling, compressive strain, gap spacing, and reinforcement damage after loading. In this study, a numerical model was also developed using the finite element software ABAQUS, and the flexural response of the NAC and SAC beams under different fire times was simulated. The results of the numerical model showed a good agreement with the experimental results. Using the numerical model, the influence of several important parameters on the ultimate capacity of the SAC beams for different fire exposure times was studied.

This investigation aims to present a new approach to study the effect of using polymer latex on the performance of latex cement co-matrix strength. This study was carried out to investigate the effect of latex addition with styrene butadiene rubber as chemical base on cement matrix participation ratio in strength of modified cement paste. Degree of hydration, and compressive strength were measured to evaluate the effect of latex addition on cement participation ratio in latex modified co-matrix strength. According to the new approach, latex network has a great participation ratio in co-matrix strength. The second stage in this study shows an attempt to evaluate the latex participation ratio in mortar and concrete strength with different latex chemical bases. The new approach considers the latex with chemical base of acrylic ester, and polyvinyl acetate has similar effect of styrene butadiene rubber. Effect of latex particles size on latex network strength was studied using the new approach. The test results indicated that the latex participation ratio in co-matrix strength is influenced by type of cement matrix, type of curing, latex type, latex solid/water ratio, strength type and age. For modified concrete, when the SBR solid/water ratio increases the latex participation ratios in flexural and pull out bond strength increases. Generally, the latex participation ratio in co-matrix strength decreases as latex particle size increases.

The purpose of this study is to research both the performance of the reinforced concrete beams without fiber and the performance of the reinforced concrete beams with fiber. For this purpose, the experimental load-displacement curves of beams were formed and the areas under these curves were compared. According to the results of this comparison, it is concluded that the reinforced concrete beams with polypropylene fiber are more ductile. The dimension of the used beam-samples for test in this study is 20x30 cm, their length is 200 cm and their scale is ½. The reinforced concrete reference-beams are produced as two items and the reinforced concrete beams with P-0.60 kg/m 3 polypropylene fiber are produced as three items.

The development of polymerkoncrete composites is directed at both improved and new construction materials by combining the ancient technology of hydraulic-cementconcrete with the modern technology of polymers. The need for such materials has always existed since the traditional construction material portland-cement-concrete (PCC) suffers the drawbacks of little or no resistance to chemical attack; rapid deterioration under freezelthaw conditions due to cyclic temperature changes; low tensile, shear and bond strengths; and inherent micro-structural menaces (voids, shrinkage-cracks, capillaries) which, individually or in combination with each other, shorten the service life of the structures.

This study compares the fiber/matrix bonding strength and flexural properties of bundle-type polyamide fibers to those of hooked-end steel fibers. Their fracture behavior upon impact with a high-velocity projectile is also assessed in terms of penetration depth, crater diameter and rear-side scabbing. The results obtained demonstrate that the bundle-type polyamide fibers undergo fracture without fiber pullout because of the increased interfiber gap and specific surface area for bonding, but exhibit poorer flexural fracture behavior with a lower flexural strength and fracture energy when compared to hookedend steel fibers. Yet despite this, concrete reinforced with bundle-type fibers is shown to more effectively suppress scabbing during high-velocity impact, which is attributed to a more efficacious dispersion of shock stress due to the increased number of individual fibers.

This pressent research investigates the mechanical properties of Waste Rubber Fibers Lightweight Coarse Aggregate Concrete (WRFLWAC) mixture. Also, the shear behaviors of 12 RC beams contain opening are investigated. The main study parameters are: The opening location, the waste rubber fiber ratio and the shear reinforcement. Deflection values and cracks are registered at each load step; also the cracking or service and failure loads are recorded. The existing of an opening in beams lessens the strength and shear and flexural rigidity of beams with a percentage depending on the position of opening, shear reinforcement and waste rubber fiber ratio. The position of opening influence the strength of tested beams and the most critical case noticed when the opening made near the support. The increase in waste rubber ratio is found to be significant on service (cracking) and ultimate loads of tested concrete beams. The numerical (finite element) technique is used trace the behavior with increasing opening size. It is find that the service (cracking) and ultimate loads decreased with increasing opening size. The laboratory and analytical results are obtained to be in good agreements.

This paper investigates the use of fly ash as a replacement for sand in polymer concrete ͑PC͒. It is shown that a replacement of 15% by weight of sand with fly ash improves the compressive strength of unreinforced PC cylinders by about 30% and the flexural strength of steel-reinforced PC beams by about 15%. Other improvements in properties are relatively minor and include the tensile bond strength of PC under thermal cycling and the creep compliance of the PC under sustained loading. The replacement of sand with fly ash, however, does not seem to have an impact on the shear strength of PC. Potential applications of PC using fly ash are numerous, including thin overlays on bridges and floors, repairing concrete bridges and pavements, and the production of precast components such as wall panels, floor blocks, and underground vaults.

Polyolefin fiber is a new type of fiber that was used in concrete to improve some of the poor properties of concrete including; tensile strength, ductility, and fracture energy. In this research, the contribution of Polyolefin fiber in improving the properties of hardened concrete was examined by adding polyolefin fibers to mix with different fiber content. The polypropylene fibers were added as a ratio of 0.5, 0.75, 1.0, 1.5, and 2% of concrete volume. Destructive and non-destructive tests were carried out: slump, compression, splitting, and bending, Schmidt Hammer, and ultrasonic pulse velocity tests. The results showed that, as the polyolefin fiber content increases, the workability of concrete reduces dramatically. The experimental findings demonstrate that the concrete tensile strength and ductility were improved by a small improvement in overall compressive strength. The results show that the compressive strength increased gradually with the increase in fiber content of up to 1.5%, and then, the compressive strength starts to decrease. However, the tensile strength increases continuously with the fiber content increasing. A good relationship was obtained between the destructive and nondestructive tests.

Plastic waste has been significantly increasing globally. Manufacturing procedures, service sectors, and municipal solid waste all produce a lot of waste plastic items. Concern over the environment and how to dispose of the generated waste has increased due to the rise in plastic waste. Additionally, the use of PET in concrete manufacturing should minimize concerns with plastic waste management and carbon dioxide emissions recycling plastic waste, thus replacing the need to dispose of it in a landfill, which has a limited capacity. One alternative is to develop "green concrete" by using plastic waste as a recycled ingredient in concrete buildings. However, before any structure is constructed out of concrete that contains plastic, it is important to know how the use of PET in concrete affects the concrete properties and structural behavior. Especially the shear strength of concrete beams, which is one of the fundamental problems in civil engineering. Therefore, this study serves as an overview of experiments that substituted polyethylene terephthalate (PET) for concrete as a volume ratio additive. It provides information on the mix design and behavior of concrete when PET is utilized.

The purpose of this study is to study behaviour of high strength reinforced concrete of grade 60 incorporating silica fumes by replacement at 8%, 12%, 16%, and 20% to weight of cement with water cement ratio of 0.3 cured in room temperature under static load. Structure properties have been investigated are crack pattern and location occur, deflection and modulus of elasticity due to bending of reinforced concrete respectively. Four numbers of beam with respective percentage of silica fumes are casted and underwent static load test to failure. This laboratory study are done in the Civil Engineering Laboratory, UiTM Shah Alam by using 1000KN Universal Testing Machine. The result obtain shows by replacing certain percentage of silica fumes (SF) into concrete have increase the concrete strength and 16% of replacement are give the best result such as higher concrete compression strength and higher ultimate load at failure. The results also show the different behaviour of beam contain dif...

Polymeric material plays a vital role in construction industry for the past 50 years and there are lot of researches on going in different countries to use the polymers in construction for various applications. Polymer concrete is a type of sustainable concrete which is totally free from cement and water as binder thereby possessing various advantages towards green concrete than conventional Portland Cement Concrete. In this paper, authors developed a mix for polymer concrete using Isophthalic resin of more than 60 MPa compressive strength for manufacturing inspection covers and frames. Developed Polymer concrete possessing various advantages like higher mechanical properties, high durability properties, rapid hardening and very good acid resistant properties can be used in various applications in architecture, construction, chemical, petroleum industries, etc. The different aspects of developed Isophthalic Polyester Polymer Concrete (IPPC), its applications towards sustainable construction in various industries are discussed in this paper.

Two major problems arise when concrete is exposed to elevated temperatures. One is the deterioration in mechanical properties of concrete and the other problem is spalling of concrete. In recent times, the inclusion of polypropylene fibers had been reported to be a feasible method to prevent spalling of concrete subjected to elevated temperature. Additional problems arise due to the fact that by adding polypropylene fibers, the residual properties of heated concrete may be adversely affected. The essential objective of this work is to investigate the effect of incorporation of polypropylene fibers or/and steel fibers on the residual properties of lightweight concrete made from porcelinite aggregate after subjected to elevated temperatures. The concrete specimens heated to target temperatures of 100, 200, 400, 600 and 800 o C, at a rate of 10 o C per minute. When the target temperature was reached, the specimens were kept at that temperature for 2 hours and then allowed to cool to room temperature by natural cooling. For each type of concrete, compressive strength, splitting tensile strength, static modulus of elasticity, and thermal expansion strains were determined before and after exposing the concrete to the target elevated temperatures. Experimental results indicated that polypropylene fiber-reinforced LWAC showed more reduction in its residual mechanical properties compared to plain LWAC. These different are more pronounced at exposure temperature of 200 and 400 o C. Average differences of 30,25 and 20 percent were observed in static modulus of elasticity, splitting tensile strength and compressive strength respectively, for specimens heated up to 400 o C. The addition of steel fibers inside the polypropylene fiber concrete would improve the residual mechanical properties of heated concrete at temperature range 200 to 600 o C. On average, the improvement ranged from 9 to 20 percent.

We have fabricated the concrete reinforced polypropylene fiber with styrene-butadiene rubber latex bonding agent of concrete in different ratio. The prepared concrete employed with structural studies using FTIR and XRD spectra. An FTIR spectrum shows the important characteristics peaks of polypropylene fiber and styrene-butadiene rubber along with silica peaks. XRD pattern indicates that concrete crystal structure of three polymorphs such orthorhombic, triclinic and monoclinic phase. SEM image indicates that the above 10 wt % of polypropylene fiber causes small hairline cracks on its surface. It is found that the tensile strength increases with increase in different weight percentage of polypropylene fiber up to 10 wt %. This is may be due to the high compactness and reduction in porosity of the concrete block. It is also important to note that the water reduce admixture such as Polycarboxylates in required ratio’s significantly effects on capillary threshold by reducing 8-12 % of w...

Nylon fibers are used as strengthening material to increase the mechanical properties of concrete.In thisstudy mechanical properties of concrete containing latex modified nylon fiber reinforced concrete wasassessed with fractional substitution of cement by flyash for M40 grade concrete at 7 days, 14 days and 28days of curing. The dosage of fibres used in this study was 0.05%, 0.1% and 0.15% of volume fraction.Cement was replaced with fly ash at a percentage of 10%, 15%, 20% by weight. SBR latex was varied at arate of 0.05%, 0.1%, 0.15% to the total cementitious content in concrete. Cube, cylinder and prism specimensare tested to determine the compressive, split tensile and flexural strength at 7 days and 28 days curing.Results shows that Nylon fiber reinforced concrete with 0.15% of fiber, 0.05% SBR Latex with 10% hashigher influence on flexural strength, split tensile strength and compressive strength of concrete.

In this study, the strengthening and toughening effects of polymeric materials on the high performance concrete (HPC) were investigated. The HPC was produced using ordinary Class 52.5 N Portland cement, silica fume and superplasticiser. The selected polymers included styrene-butadiene-rubber (SBR) latex; polyvinylidene chloride (PVDC); and linear low density polyethylene (LLDPE) with additive of 1.5%, 3% and 5% by weight in the cement content. The measured mechanical and fracture properties included compressive and tensile strengths; the modulus of rupture; fracture energy; fracture toughness and dynamic elastic modulus. The results indicate that the polymers used increase the compressive and tensile strengths of the HPC, in particular for the 1.5% weight content, but did not enhance other properties.

This investigation aims to present a new approach to study the effect of using polymer latex on the performance of latex cement co-matrix strength. This study was carried out to investigate the effect of latex addition with styrene butadiene rubber as chemical base on cement matrix participation ratio in strength of modified cement paste. Degree of hydration, and compressive strength were measured to evaluate the effect of latex addition on cement participation ratio in latex modified co-matrix strength. According to the new approach, latex network has a great participation ratio in co-matrix strength. The second stage in this study shows an attempt to evaluate the latex participation ratio in mortar and concrete strength with different latex chemical bases. The new approach considers the latex with chemical base of acrylic ester, and polyvinyl acetate has similar effect of styrene butadiene rubber. Effect of latex particles size on latex network strength was studied using the new approach. The test results indicated that the latex participation ratio in co-matrix strength is influenced by type of cement matrix, type of curing, latex type, latex solid/water ratio, strength type and age. For modified concrete, when the SBR solid/water ratio increases the latex participation ratios in flexural and pull out bond strength increases. Generally, the latex participation ratio in co-matrix strength decreases as latex particle size increases.

Ferrocement panels are thin-section panels that are widely used in lightweight construction. Due to lesser flexural stiffness, they are susceptible to surface cracking. Water may penetrate through these cracks and may cause corrosion of conventional thin steel wire mesh. This corrosion is one of the major factors which affect the load-carrying and durability of ferrocement panels. There is a need to improve the mechanical performance of ferrocement panels either through using some non-corrodible reinforcing mesh or through improving the cracking behavior of the mortar mix. In the present experimental work, PVC plastic wire mesh is employed to address this problem. SBR latex and polypropylene (PP) fibers are also utilized as admixtures to control the micro-cracking and improve the energy absorption capacity. The main idea is to improve the structural performance of ferrocement panels that may be utilized in lightweight, low-cost house construction and sustainable construction. The ul...

This study deals with, experimentally, the effect of flange dimensions on shear behavior of normal strength concrete (NSC) and self-compacting concrete (SCC) double Tee beams. Twelve beam specimens as well as a series of control specimens are tested. The beam specimens were divided into two groups (based on concrete type) and each group are divided into five subgroups (based on flange dimensions).The webs dimensions, beam depth, beam length, spacing between webs, longitudinal (tension) reinforcement and transverse reinforcement (stirrups) were kept constant in all beam specimens. Experimental results showed that the ultimate capacity increased about (6%12) and (9%-20) when the flange width (dimensions) increased from (320mm) to (450mm) for NSC and SCC respectively. Presence of large compression flange lead to increase the stiffness of tested beams due to contribution of additional concrete parts, and this leads to increase in carrying capacity.

This investigation aims to present a new approach to study the effect of using polymer latex on the performance of latex cement co-matrix strength. This study was carried out to investigate the effect of latex addition with styrene butadiene rubber as chemical base on cement matrix participation ratio in strength of modified cement paste. Degree of hydration, and compressive strength were measured to evaluate the effect of latex addition on cement participation ratio in latex modified co-matrix strength. According to the new approach, latex network has a great participation ratio in co-matrix strength. The second stage in this study shows an attempt to evaluate the latex participation ratio in mortar and concrete strength with different latex chemical bases. The new approach considers the latex with chemical base of acrylic ester, and polyvinyl acetate has similar effect of styrene butadiene rubber. Effect of latex particles size on latex network strength was studied using the new approach. The test results indicated that the latex participation ratio in co-matrix strength is influenced by type of cement matrix, type of curing, latex type, latex solid/water ratio, strength type and age. For modified concrete, when the SBR solid/water ratio increases the latex participation ratios in flexural and pull out bond strength increases. Generally, the latex participation ratio in co-matrix strength decreases as latex particle size increases.

Polyolefin fiber is a new type of fiber that was used in concrete to improve some of the poor properties of concrete including; tensile strength, ductility, and fracture energy. In this research, the contribution of Polyolefin fiber in improving the properties of hardened concrete was examined by adding polyolefin fibers to mix with different fiber content. The polypropylene fibers were added as a ratio of 0.5, 0.75, 1.0, 1.5, and 2% of concrete volume. Destructive and non-destructive tests were carried out: slump, compression, splitting, and bending, Schmidt Hammer, and ultrasonic pulse velocity tests. The results showed that, as the polyolefin fiber content increases, the workability of concrete reduces dramatically. The experimental findings demonstrate that the concrete tensile strength and ductility were improved by a small improvement in overall compressive strength. The results show that the compressive strength increased gradually with the increase in fiber content of up to 1.5%, and then, the compressive strength starts to decrease. However, the tensile strength increases continuously with the fiber content increasing. A good relationship was obtained between the destructive and nondestructive tests.

Ferrocement panels are thin-section panels that are widely used in lightweight construction. Due to lesser flexural stiffness, they are susceptible to surface cracking. Water may penetrate through these cracks and may cause corrosion of conventional thin steel wire mesh. This corrosion is one of the major factors which affect the load-carrying and durability of ferrocement panels. There is a need to improve the mechanical performance of ferrocement panels either through using some non-corrodible reinforcing mesh or through improving the cracking behavior of the mortar mix. In the present experimental work, PVC plastic wire mesh is employed to address this problem. SBR latex and polypropylene (PP) fibers are also utilized as admixtures to control the micro-cracking and improve the energy absorption capacity. The main idea is to improve the structural performance of ferrocement panels that may be utilized in lightweight, low-cost house construction and sustainable construction. The ul...

This investigation aims to present a new approach to study the effect of using polymer latex on the performance of latex cement co-matrix strength. This study was carried out to investigate the effect of latex addition with styrene butadiene rubber as chemical base on cement matrix participation ratio in strength of modified cement paste. Degree of hydration, and compressive strength were measured to evaluate the effect of latex addition on cement participation ratio in latex modified co-matrix strength. According to the new approach, latex network has a great participation ratio in co-matrix strength. The second stage in this study shows an attempt to evaluate the latex participation ratio in mortar and concrete strength with different latex chemical bases. The new approach considers the latex with chemical base of acrylic ester, and polyvinyl acetate has similar effect of styrene butadiene rubber. Effect of latex particles size on latex network strength was studied using the new approach. The test results indicated that the latex participation ratio in co-matrix strength is influenced by type of cement matrix, type of curing, latex type, latex solid/water ratio, strength type and age. For modified concrete, when the SBR solid/water ratio increases the latex participation ratios in flexural and pull out bond strength increases. Generally, the latex participation ratio in co-matrix strength decreases as latex particle size increases.

This investigation aims to present a new approach to study the effect of using polymer latex on the performance of latex cement co-matrix strength. This study was carried out to investigate the effect of latex addition with styrene butadiene rubber as chemical base on cement matrix participation ratio in strength of modified cement paste. Degree of hydration, and compressive strength were measured to evaluate the effect of latex addition on cement participation ratio in latex modified co-matrix strength. According to the new approach, latex network has a great participation ratio in co-matrix strength. The second stage in this study shows an attempt to evaluate the latex participation ratio in mortar and concrete strength with different latex chemical bases. The new approach considers the latex with chemical base of acrylic ester, and polyvinyl acetate has similar effect of styrene butadiene rubber. Effect of latex particles size on latex network strength was studied using the new approach. The test results indicated that the latex participation ratio in co-matrix strength is influenced by type of cement matrix, type of curing, latex type, latex solid/water ratio, strength type and age. For modified concrete, when the SBR solid/water ratio increases the latex participation ratios in flexural and pull out bond strength increases. Generally, the latex participation ratio in co-matrix strength decreases as latex particle size increases.

This investigation aims to present a new approach to study the effect of using polymer latex on the performance of latex cement co-matrix strength. This study was carried out to investigate the effect of latex addition with styrene butadiene rubber as chemical base on cement matrix participation ratio in strength of modified cement paste. Degree of hydration, and compressive strength were measured to evaluate the effect of latex addition on cement participation ratio in latex modified co-matrix strength. According to the new approach, latex network has a great participation ratio in co-matrix strength. The second stage in this study shows an attempt to evaluate the latex participation ratio in mortar and concrete strength with different latex chemical bases. The new approach considers the latex with chemical base of acrylic ester, and polyvinyl acetate has similar effect of styrene butadiene rubber. Effect of latex particles size on latex network strength was studied using the new approach. The test results indicated that the latex participation ratio in co-matrix strength is influenced by type of cement matrix, type of curing, latex type, latex solid/water ratio, strength type and age. For modified concrete, when the SBR solid/water ratio increases the latex participation ratios in flexural and pull out bond strength increases. Generally, the latex participation ratio in co-matrix strength decreases as latex particle size increases.