Crystalline admixtures(CA),also known as permeability reducer admixtures,are used in binder-based materials to improve concrete durability by reducing water permeability depth,increasing compressive strength,and stimu...Crystalline admixtures(CA),also known as permeability reducer admixtures,are used in binder-based materials to improve concrete durability by reducing water permeability depth,increasing compressive strength,and stimulating crack healing.The purpose of this study is to evaluate the potential of crystalline admixtures to enhance the self-healing characteristics and durability attributes of concrete and to contribute to the understanding of their role in the design of long-term efficiency and sustainability.The 28 days specimens of M40 grade concrete were prepared by adding CA and cast as 150 mm cubes,25×25×285 mm prisms and disks with a diameter of 100 mm and height of 50 mm.All samples were then tested for compressive strength,water permeability,dry shrinkage,sodium sulfate attack test,Rapid Chloride Migration Test(RCMT),and rapid chloride penetration test(RCPT)to study the behavior of incorporating crystalline admixtures in concrete.The conclusion drawn from this study was that the addition of a crystalline admixture of 0.8%resulted in an increase in the compressive strength by 7.98%and a decrease in water penetration depth through the cube by 71.5%,while the dry shrinkage of the specimen incorporated with the crystalline admixture was 65.21%less than that of the specimen without the crystalline admixture.These results substantiate the beneficial role of CA in increasing the durability of concrete through increased strength,lower permeability,and better dimensional stability,thus making crystalline admixtures beneficial for incorporation into high-performance concrete applications.展开更多
Fiber reinforcement significantly enhances the strength,toughness,and durability of concrete by reducing the propagation of microcracks in the concrete matrix.With the rising demand for high-performance concrete(HPC),...Fiber reinforcement significantly enhances the strength,toughness,and durability of concrete by reducing the propagation of microcracks in the concrete matrix.With the rising demand for high-performance concrete(HPC),this study investigates the mechanical properties of HPC with varying proportions of polypropylene(PP)and steel(ST)fibers.Supplementary cementitious materials(SCMs)toward partial replacement of ordinary Portland cement(OPC)were incorporated to prepare HPC mixes as a ternary composite system using Fly Ash(FA),Silica Fume(SF),and Ground Granulated Blast Furnace Slag(GGBS).Each HPC mix comprised two SCMs,accounting for 20%of the mass fraction of the OPC binder.The study encompassed fiber percentages ranging from 0 to 0.075%PP and 0 to 2%ST,incorporating them into the HPC mixes with gradual increases of 0.025%for PP and 0.5%for ST fiber by mass fraction.All HPC mixes were tested for mechanical properties using compressive and split tensile strength tests.The influence of SCMs on HPC was studied using X-ray diffraction(XRD)for microstructural analyses.It was found that the compressive and split tensile strengths of HPC increased up to an optimal fiber percentage and then decreased.A comparison of the test results of high-performance fiber-reinforced concrete with those of plain HPC revealed significant improvements in compressive and splitting tensile strengths by 26.59%and 57.74%,respectively.Also,the XRD analysis revealed that the composition of the SCMs in HPC was a significant and effective solution for the mechanical properties of the concrete.展开更多
文摘Crystalline admixtures(CA),also known as permeability reducer admixtures,are used in binder-based materials to improve concrete durability by reducing water permeability depth,increasing compressive strength,and stimulating crack healing.The purpose of this study is to evaluate the potential of crystalline admixtures to enhance the self-healing characteristics and durability attributes of concrete and to contribute to the understanding of their role in the design of long-term efficiency and sustainability.The 28 days specimens of M40 grade concrete were prepared by adding CA and cast as 150 mm cubes,25×25×285 mm prisms and disks with a diameter of 100 mm and height of 50 mm.All samples were then tested for compressive strength,water permeability,dry shrinkage,sodium sulfate attack test,Rapid Chloride Migration Test(RCMT),and rapid chloride penetration test(RCPT)to study the behavior of incorporating crystalline admixtures in concrete.The conclusion drawn from this study was that the addition of a crystalline admixture of 0.8%resulted in an increase in the compressive strength by 7.98%and a decrease in water penetration depth through the cube by 71.5%,while the dry shrinkage of the specimen incorporated with the crystalline admixture was 65.21%less than that of the specimen without the crystalline admixture.These results substantiate the beneficial role of CA in increasing the durability of concrete through increased strength,lower permeability,and better dimensional stability,thus making crystalline admixtures beneficial for incorporation into high-performance concrete applications.
基金financed by the Science and Engineering Research Board,India,in Project No.EEQ/2023/000130CSIR-India in Project No.MLP072002.
文摘Fiber reinforcement significantly enhances the strength,toughness,and durability of concrete by reducing the propagation of microcracks in the concrete matrix.With the rising demand for high-performance concrete(HPC),this study investigates the mechanical properties of HPC with varying proportions of polypropylene(PP)and steel(ST)fibers.Supplementary cementitious materials(SCMs)toward partial replacement of ordinary Portland cement(OPC)were incorporated to prepare HPC mixes as a ternary composite system using Fly Ash(FA),Silica Fume(SF),and Ground Granulated Blast Furnace Slag(GGBS).Each HPC mix comprised two SCMs,accounting for 20%of the mass fraction of the OPC binder.The study encompassed fiber percentages ranging from 0 to 0.075%PP and 0 to 2%ST,incorporating them into the HPC mixes with gradual increases of 0.025%for PP and 0.5%for ST fiber by mass fraction.All HPC mixes were tested for mechanical properties using compressive and split tensile strength tests.The influence of SCMs on HPC was studied using X-ray diffraction(XRD)for microstructural analyses.It was found that the compressive and split tensile strengths of HPC increased up to an optimal fiber percentage and then decreased.A comparison of the test results of high-performance fiber-reinforced concrete with those of plain HPC revealed significant improvements in compressive and splitting tensile strengths by 26.59%and 57.74%,respectively.Also,the XRD analysis revealed that the composition of the SCMs in HPC was a significant and effective solution for the mechanical properties of the concrete.
