Liang Huo

Effect of Fiber on Mechanical Properties and Fire Resistance of C100 Ultra High Strength Concrete

It used conventional techniques and materials prepared high strength fiber reinforced concrete whose strength class is above C100 and it studied the effect of fiber content on the mechanical properties and elastic modulus. It also studied the fire resistance of fiber reinforced concrete. Results suggest that the strength of 28d concrete is above 100MPa and the highest strength is 126.4MPa. Under the same ratio conditions, the greater the volume content of steel fiber concrete flexural strength, the splitting tensile strength is higher. The steel fiber volume only affect elastic modulus of concrete little. When it heats to 300 °C, the no fiber concrete comminuted burst while the fiber concrete does not damaged at elevated temperatures up to 300 °C and continue to heat up, the crushing damage occurs at about 460 °C. Has not been damaged concrete specimens at 300 °C, the quality have emerged about 3% decline, while the compressive strength increased by 35%-52%, the highest strength reached 180.3MPa.

Research on the Application of Expansive Agent in C60 Self-Compacting Concrete

It analyzed the performance, mechanical properties, volume stability, microstructure of hydration cementitious material of C60 self-compacting expansion concrete, which dependent on CSA to expansive ettringite source for the expansion. Results suggest that on the same curing conditions, C60 self-compacting concrete with the water-cement ratio of 0.32 admixture CSA expansive agent can effectively control the shrinkage of concrete, so that it is slightly inflated. The dosage of CSA expansive is higher, early strength of C60 self-compacting concrete is lower and its late strength declines small. It is affected little for the slump and extended degree of concrete under the superplasticizer by the expansive agent. SEM results show that CSA expansion agent can improve the pore structure of hydrated cement paste system with low water-binder ratio. The gel phase after hardening has good compactness and ettringite needlelike crystals mostly distribute at each interface layer.