Papers by Author: Jian Tong Ding

Abstract: In order to investigate influence of aggregates on cracking resistance of concrete at early age, four kinds of aggregates, i.e. syenite, basalt, marble and sandstone, were used for the test on cracking resistance of hydraulic concretes by the temperature stress testing machine. Analogy analysis was carried out with test results of concretes with two gradings of aggregates. The results show that aggregates affect elastic modulus, thermal expansion coefficients and tensile creep behavior of concrete at early age. However, the temperature rise of concrete was slightly affected by various types and gradings of aggregate. Moreover, the cracking temperature is reliably to be used to quantitatively evaluate the influence of aggregates on cracking resistance of concrete at early age.

Abstract: In order to evaluate the crack resistance of high strength fly ash concrete, concretes with different contents of silica fume and fly ash were compared with same strength grade by adjusting water to binder ratio. Compared with the concrete with 5% silica fume plus 35% fly ash，concrete with 40% fly ash has same mechanical properties and tensile strain as well as lower drying shrinkage. Complex crack resistance of high strength fly ash concretes were evaluated by Temperature Stress Testing Machine (TSTM). The results show that fly ash concretes have outstanding crack resistance because of higher allowable temperature differential and lower cracking temperature.