جستجوی مقالات مرتبط با کلیدواژه « Self-compacting cementitious composites » در نشریات گروه « عمران »

Self-compacting composite concrete is known as a cement composite with high performance and adhesion. This composite has a lot of psychological capability and efficiency. Concrete failure depends on the formation of cracks and microcracks. As the load increases, the microcracks join together to form cracks. To solve this problem and also to create homogeneous conditions, in recent years, thin fibers of fiber in the entire volume of concrete are used. Fiber concrete is actually a type of cementitious composite that increases its tensile and compressive strength by using reinforcing fibers inside the concrete mix. In this study, the effect of adding materials (Microsilica Fume, Fly Ash, GGBFS) and sinusoidal steel fibers (corrugated) on the mechanical properties of self-compacting cement composite was investigated in 9 mixing designs. For this purpose, cement alternative additives in the amount of 10% by weight of cementitious materials and steel fibers in the amount of 1% of the volume of cement composite were used in the mixing design. In the compressive strength test, the sample with 1% steel fibers had a 4.5% increase in strength compared to the reference sample, which showed a very low effect of steel fibers on the compressive strength. Also, the use of microsilica by 10% by weight of cement substitute increased the amount of compressive strength by 6.6%, which due to the property of microsilica in increasing resistance, this result was not far from the eye. In general, the use of steel fibers had no effect on the results of compressive strength, capillarity, and water absorption, but the changes in other test results compared to the reference sample were quite noticeable and expected due to the use of steel fibers.

The use of concrete in industry is expanding. Self-compacting composite concrete is known as a cement composite with high performance and adhesion. This composite has a lot of psychological capabilities and efficiency, so that the use of this concrete, in addition to reducing construction time, also reduces costs. Self-compacting composites fit into the mold without the need for vibration and pass through the smallest seam. In this study, the effects of adding microsilica, fly ash and GGBFS pozzolan on the mechanical properties of self-compacting cement composite were investigated in 8 mixing designs. In making samples, 3 alternative cement additives at the rate of 10% were used in different mixing designs. In the compressive strength test, the sample with 10% microsilica increased the resistance by 5.4% more than the reference sample, which showed that the addition of microsilica increases the strength and water absorption in the samples. However, these pozzolans reduce the flow of self-compacting concrete. On the other hand, in the design of air ash mixtures, the resistance was reduced, but no significant changes were observed for slag. In total, other experiments such as tensile strength, flexural strength, water absorption, capillary, ultrasonic pulse velocity and impact resistance were performed on the mixing design.