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FIGURE 2: Compressive Strength Of Concrete Mixes The compressive strength test of cylindrical specimens was done utilizing a compression tester. In order to find out the effect of adding SBR Sika-Latex on the development of compressive strength of modified concrete compared to unmodified concrete (reference mix), the testing was conducted at different ages (7, 28, 56 and 90 days). Figure (2) displays the relationship between the compressive strength of concrete mixes and age.

Figure 2 Compressive Strength Of Concrete Mixes The compressive strength test of cylindrical specimens was done utilizing a compression tester. In order to find out the effect of adding SBR Sika-Latex on the development of compressive strength of modified concrete compared to unmodified concrete (reference mix), the testing was conducted at different ages (7, 28, 56 and 90 days). Figure (2) displays the relationship between the compressive strength of concrete mixes and age.

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TABLE 1: Chemical Composition of the Cemen TABLE 2: Physical Properties of the Cement 2.1.1 Cement: In the current investigation, ordinary Portland cement was employed, which was made in accordance with Iraqi standards specifications (IQS) NO.5[10]. The physical and chemical properties of the cement used are shown in tables (1) and (2), respectively.
TABLE 1: Chemical Composition of the Cemen TABLE 2: Physical Properties of the Cement 2.1.1 Cement: In the current investigation, ordinary Portland cement was employed, which was made in accordance with Iraqi standards specifications (IQS) NO.5[10]. The physical and chemical properties of the cement used are shown in tables (1) and (2), respectively.
2.1.2 Fine aggregate: The sand used in the study is local river sand, the sieve analysis of the sand is shown in table (3), where it was found that it conforms to the limits of specification (ASTMC33) [11], the fineness modulus of the used sand is (2.74), its specific weight is (2.6) and the absorption is (1%).
2.1.2 Fine aggregate: The sand used in the study is local river sand, the sieve analysis of the sand is shown in table (3), where it was found that it conforms to the limits of specification (ASTMC33) [11], the fineness modulus of the used sand is (2.74), its specific weight is (2.6) and the absorption is (1%).
TABLE (3): Grading of Fine Aggregate 2.1.3 Coarse aggregate: Local rounded river gravel was used. Table (4) shows the sieve analysis of gravel. which showed that the grade of the used gravel conforms to the limits of (ASTMC33) [11], the maximum aggregate size is (20 mm), the specific weight of the gravel (2.61) and the absorption (0.8%).
TABLE (3): Grading of Fine Aggregate 2.1.3 Coarse aggregate: Local rounded river gravel was used. Table (4) shows the sieve analysis of gravel. which showed that the grade of the used gravel conforms to the limits of (ASTMC33) [11], the maximum aggregate size is (20 mm), the specific weight of the gravel (2.61) and the absorption (0.8%).
TABLE (4): Grading of Normal and Recycle Coarse Aggregate 2.1.4 SBR Latex: The effect of adding (Sika-latex), a type of locally available (styrene-butadiene rubber latex) (SBR Latex), to concrete mixes to obtain latex-modified concrete, was analyzed. This material is characterized by its high adhesion. It is a flexible material that resists water, does not corrode, resists chemicals, reduces shrinkage [3]. The properties of SBR sika latex utilized in the investigation are shown in Table (5).
TABLE (4): Grading of Normal and Recycle Coarse Aggregate 2.1.4 SBR Latex: The effect of adding (Sika-latex), a type of locally available (styrene-butadiene rubber latex) (SBR Latex), to concrete mixes to obtain latex-modified concrete, was analyzed. This material is characterized by its high adhesion. It is a flexible material that resists water, does not corrode, resists chemicals, reduces shrinkage [3]. The properties of SBR sika latex utilized in the investigation are shown in Table (5).
TABLE (5): SBR Sika-Latex Properties 2.2 Concrete mixes
TABLE (5): SBR Sika-Latex Properties 2.2 Concrete mixes
FIGURE 1: Slump Test Pinner ns, a To establishing the workability of concrete mixes, a slump test was conducted. Where the slump test was measurec for unmodified concrete mixes and modified concrete mixes with the corporation of (SBR sika-latex) according t¢ (ASTM C143) [15] as shown in figure (1).
FIGURE 1: Slump Test Pinner ns, a To establishing the workability of concrete mixes, a slump test was conducted. Where the slump test was measurec for unmodified concrete mixes and modified concrete mixes with the corporation of (SBR sika-latex) according t¢ (ASTM C143) [15] as shown in figure (1).
TABLE (6): Mix Design To perform the aforementioned tests, standard cylinders with dimensions (150 * 300 mm) were cast for all mixes, (24) specimens for each mix, meaning that the total number of specimens was (120). After casting the specimens were treated with water (standard treatment) for 28 days. Compressive and indirect tensile testing were performed with ages (7, 28, 56, and 90days) according to (ASTM C39-05) and (ASTM C496-17) respectively [12][13]. Regarding the speed of sound waves, it was measured at ages (56 and 90 days). Before testing the specimens, the surface of the specimens was leveled by capping, which was carried out according to ASTM C617—98 [14]. It is worth noting that the results of each testing and at any age represent an average of the results of three specimens.
TABLE (6): Mix Design To perform the aforementioned tests, standard cylinders with dimensions (150 * 300 mm) were cast for all mixes, (24) specimens for each mix, meaning that the total number of specimens was (120). After casting the specimens were treated with water (standard treatment) for 28 days. Compressive and indirect tensile testing were performed with ages (7, 28, 56, and 90days) according to (ASTM C39-05) and (ASTM C496-17) respectively [12][13]. Regarding the speed of sound waves, it was measured at ages (56 and 90 days). Before testing the specimens, the surface of the specimens was leveled by capping, which was carried out according to ASTM C617—98 [14]. It is worth noting that the results of each testing and at any age represent an average of the results of three specimens.
FIGURE 3: Tensile Strength of Concrete Mixes One of the things that can be distinguished from the figure is that the tensi e strength of modified and unmodified concrete increases with age. By comparing the results of the indirect tensile strength of polymer-modified concrete and unmodified concrete (the reference mix), we find that an increase in the h decreased by (5.3%, 18.4%, 26.3%, and 36.8 %) for e strength was (7.5%, 15%, 25%, and 4 S 35%) for the percentages (2%, 4%,6%, and 8%), respectively, at the age of (5 fhe reason for the decrease in tensile strength is due phenomenon of foaming [25] For this reason, researchers and the indirect tensile strength is illustra’ he tensile strength, as the tensile strengt %,6% and 8%) respectively at age (28days), Whereas, the decrease in tensi he amount of decrease in tensile strength (3.1%, 19.2%, 30%, and 38%) was 6d for o the formation of hese bubbles in polymer modified concre ed in Figure (4 trength increases the tensile strength, and the obtained relationship revealed th he two properties and this is clear from the high correlation coefficient. percentage of SBR Si ays). As for at the percentages (2%, 4 bubbles due to the occurrence of the have resorted to using materials to reduce e, anti-foam materials. The relationship between the compressive strength ), where it is obvious hat the increase in ka-Latex reduces percentages (2%, age of (90 days), %,6%, and 8%). he generation of the compressive att here is an ideal rela ionship between
FIGURE 3: Tensile Strength of Concrete Mixes One of the things that can be distinguished from the figure is that the tensi e strength of modified and unmodified concrete increases with age. By comparing the results of the indirect tensile strength of polymer-modified concrete and unmodified concrete (the reference mix), we find that an increase in the h decreased by (5.3%, 18.4%, 26.3%, and 36.8 %) for e strength was (7.5%, 15%, 25%, and 4 S 35%) for the percentages (2%, 4%,6%, and 8%), respectively, at the age of (5 fhe reason for the decrease in tensile strength is due phenomenon of foaming [25] For this reason, researchers and the indirect tensile strength is illustra’ he tensile strength, as the tensile strengt %,6% and 8%) respectively at age (28days), Whereas, the decrease in tensi he amount of decrease in tensile strength (3.1%, 19.2%, 30%, and 38%) was 6d for o the formation of hese bubbles in polymer modified concre ed in Figure (4 trength increases the tensile strength, and the obtained relationship revealed th he two properties and this is clear from the high correlation coefficient. percentage of SBR Si ays). As for at the percentages (2%, 4 bubbles due to the occurrence of the have resorted to using materials to reduce e, anti-foam materials. The relationship between the compressive strength ), where it is obvious hat the increase in ka-Latex reduces percentages (2%, age of (90 days), %,6%, and 8%). he generation of the compressive att here is an ideal rela ionship between
FIGURE 4: The Relationship Between Concrete Mixes Tensile And Compressive Strength
FIGURE 4: The Relationship Between Concrete Mixes Tensile And Compressive Strength
It is clear that with an increase in the ratio of (SBR/C), the decrease in density increases, as the percentage of decrease reached (0.84%, 1.25%, 1.61% and 1.97%) for mixes containing addition ratios (2%, 4%,6% and 8%) respectively at the age of (56 days), while the decrease in density reached (0.72%, 1.24%, 1.73% and 1.89%) for the container mixes (2%, 4%,6% and 8%) respectively at the age of (90days), as shown in figure (6). The decrease in density of modified concrete is caused by the fact that the density of SBR Sika-Latex is low in comparison to the density of the matrix. [23]. FIGURE 6: The Percentages Of Decrease In The Density Of Concrete Mixes With An Increase In SBR Sika-Latex At 56 And 90 Days
It is clear that with an increase in the ratio of (SBR/C), the decrease in density increases, as the percentage of decrease reached (0.84%, 1.25%, 1.61% and 1.97%) for mixes containing addition ratios (2%, 4%,6% and 8%) respectively at the age of (56 days), while the decrease in density reached (0.72%, 1.24%, 1.73% and 1.89%) for the container mixes (2%, 4%,6% and 8%) respectively at the age of (90days), as shown in figure (6). The decrease in density of modified concrete is caused by the fact that the density of SBR Sika-Latex is low in comparison to the density of the matrix. [23]. FIGURE 6: The Percentages Of Decrease In The Density Of Concrete Mixes With An Increase In SBR Sika-Latex At 56 And 90 Days
TABLE (7): Classification Of Concrete According UP V [30]
TABLE (7): Classification Of Concrete According UP V [30]
FIGURE 7: Ultrasound Pulse Velocity Of Concrete Mixes
FIGURE 7: Ultrasound Pulse Velocity Of Concrete Mixes
It is noted from Figure (7) that the velocity of ultrasound decreases with increasing inclusion of SBR Sika-Late for polymer modified concrete for both ages compared to unmodified concrete, and that the values of UPV fo nodified concrete at the age of 90 days are less than the UPV values at the age of 56 days. The velocity of th ultrasound waves is a function of the volumetric concentration of the concrete components [28], and therefore thi lecrease in the velocity of the waves is due to the increase in porosity as a result of the generation and formation c uir voids between the aggregate and the cement paste. Since waves travel faster through dense or more dense medium 29], their speed decreases in the modified concrete because its density decreases with the increase in the percentage »f addition, as was explained in the previous section. And from observing figure (8) which illustrates the relationshi yetween the proportion of addition of SBR Sika-Latex and the compressive strength and the velocity of ultrasound fo uges (56 and 90days), it turns out that there is a relationship between the results, as the increase in the percentage o olymer added led to a decrease in the compressive strength as a result of the formation of voids between Aggregat und cement paste, meaning that the concrete becomes more porous, and these voids, in turn, lead to a reduction in th velocity of ultrasonic wave transmission through the concrete. FIGURE 8: The Relationship Between Compressive Strength And UPV Of Concrete Mixes
It is noted from Figure (7) that the velocity of ultrasound decreases with increasing inclusion of SBR Sika-Late for polymer modified concrete for both ages compared to unmodified concrete, and that the values of UPV fo nodified concrete at the age of 90 days are less than the UPV values at the age of 56 days. The velocity of th ultrasound waves is a function of the volumetric concentration of the concrete components [28], and therefore thi lecrease in the velocity of the waves is due to the increase in porosity as a result of the generation and formation c uir voids between the aggregate and the cement paste. Since waves travel faster through dense or more dense medium 29], their speed decreases in the modified concrete because its density decreases with the increase in the percentage »f addition, as was explained in the previous section. And from observing figure (8) which illustrates the relationshi yetween the proportion of addition of SBR Sika-Latex and the compressive strength and the velocity of ultrasound fo uges (56 and 90days), it turns out that there is a relationship between the results, as the increase in the percentage o olymer added led to a decrease in the compressive strength as a result of the formation of voids between Aggregat und cement paste, meaning that the concrete becomes more porous, and these voids, in turn, lead to a reduction in th velocity of ultrasonic wave transmission through the concrete. FIGURE 8: The Relationship Between Compressive Strength And UPV Of Concrete Mixes
The relationship between compressive strength and ultrasonic pulse velocity is depicted in Figure (9), as it was found that the polynomial correlation is the relationship that presented a perfect statistical relationship between (UPV) and Compressive Strength, and this is clear from the coefficient of determination (R-squared) Which is equal to (0.9992) and (0.9878) for ages (56 and 90). Where these values showed a substantial correlation between the compressive strength and the UPV in this study, as a result, this relationship can be utilized to anticipate compressive streneth. [311]. FIGURE 9: Relationship Between The Compressive Strength And UPV Dynamic modulus of elasticity It is one of the non-destructive properties that were investigated in this study, where this property was studied indirectly by taking advantage of the values of ultrasound pulse velocity and concrete density and this was done by relying on the given equation to compute the dynamic modulus of elasticity:
The relationship between compressive strength and ultrasonic pulse velocity is depicted in Figure (9), as it was found that the polynomial correlation is the relationship that presented a perfect statistical relationship between (UPV) and Compressive Strength, and this is clear from the coefficient of determination (R-squared) Which is equal to (0.9992) and (0.9878) for ages (56 and 90). Where these values showed a substantial correlation between the compressive strength and the UPV in this study, as a result, this relationship can be utilized to anticipate compressive streneth. [311]. FIGURE 9: Relationship Between The Compressive Strength And UPV Dynamic modulus of elasticity It is one of the non-destructive properties that were investigated in this study, where this property was studied indirectly by taking advantage of the values of ultrasound pulse velocity and concrete density and this was done by relying on the given equation to compute the dynamic modulus of elasticity:
FIGURE 10: Relationship Between The Dynamic Modulus Of Elastic ity And SBR Sika-Latex
FIGURE 10: Relationship Between The Dynamic Modulus Of Elastic ity And SBR Sika-Latex
FIGURE 11: Relationship Between The Dynamic Modulus Of Elastic ity And UPV It is evident from Figure (10) that there is a decrease in the dynamic modulus of elasticity of the modified concrete compared to the unmodified concrete for both ages (56 and 90 days), and that this decrease increases with the increase in the content of the percentage of SBR Sika-Latex. As mentioned previously, increasing the percentage of SBR Sika- Latex reduced the density of the specimens, and thus, this worked to reduce the dynamic modulus of elasticity. Figure (11) shows the relationship between the dynamic modulus of elasticity and UPV, as it turns out that the correlation is strong and linear, and this is clear from the value of the coefficient of determination for both ages, which reached (1 and 0.9997) and this is because the dynamic modulus of elasticity and the UPV are similarly affected by the same changes that occurred for concrete (34).
FIGURE 11: Relationship Between The Dynamic Modulus Of Elastic ity And UPV It is evident from Figure (10) that there is a decrease in the dynamic modulus of elasticity of the modified concrete compared to the unmodified concrete for both ages (56 and 90 days), and that this decrease increases with the increase in the content of the percentage of SBR Sika-Latex. As mentioned previously, increasing the percentage of SBR Sika- Latex reduced the density of the specimens, and thus, this worked to reduce the dynamic modulus of elasticity. Figure (11) shows the relationship between the dynamic modulus of elasticity and UPV, as it turns out that the correlation is strong and linear, and this is clear from the value of the coefficient of determination for both ages, which reached (1 and 0.9997) and this is because the dynamic modulus of elasticity and the UPV are similarly affected by the same changes that occurred for concrete (34).
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