Investigation and evaluation on early-age cracking resistance of high performance concrete reinforced with non-metallic fiber
摘要
High performance concrete (HPC) has been widely consumed because of its outstanding mechanical properties. Meanwhile, the large shrinkage strain of HPC easily induces cracks, which can seriously affect its durability. As steel fibers have a corrosion risk when used in HPC under the marine environment, this study investigated the crack resistance of HPC reinforced with non-metallic fibers, including the fiber types and contents. The mechanical properties, drying shrinkage, and early-age cracking testing, were conducted. Experimental results show that the hooked-end steel fiber has the highest bond strength with the HPC matrix. Adding fibers can increase the compressive and splitting tensile strength and decrease the drying shrinkage of HPC. The cracking numbers and area of early cracking testing decreased with the addition of fibers, which is close to the stress transfer and crack-bridging effect of fibers. Increasing the elastic modulus and contents of fibers achieves better anti-cracking performance. Additionally, the predicted models on compressive strength, splitting tensile strength, and ultimate drying shrinkage considering the fiber’s mechanical properties and contents were proposed with relevant regression coefficients over 0.97.