膨润土种类及掺量对塑性混凝土性能的影响

通过塑性混凝土和易性、抗压强度、弹性模量和相对渗透系数试验,对比分析钠基膨润土和钙基膨润土对塑性混凝土和易性、抗压强度、弹性模量和相对渗透系数的影响。结果表明:塑性混凝土和易性满足要求;同一龄期下随着膨润土掺量的增加,塑性混凝土的抗压强度和弹性模量都降低,但掺钠基膨润土的塑性混凝土抗压强度和弹性模量比掺钙基膨润土的塑性混凝土抗压强度和弹性模量高约1.5倍;前者的相对渗透系数小于后者;塑性混凝土中膨润土的掺量不宜超过60%,宜控制在20%～40%之间;宜用90 d龄期作为塑性混凝土力学性能试验的标准养护龄期。

Influences of types and dosage of bentonite on properties of plastic concrete

Based on the tests on plastic concrete,the respective influences of calcium-based bentonite and sodium-based bentonite on its workability,compressive strength,elastic modulus and relative permeability coefficient were comparatively studied.The test results show that the workability of plastic concrete satisfies the requirements.Under the same age,the compressive strength and the elastic modulus of plastic concrete both decrease with the increase of dosage of bentonite.However,the compressive strength and the elastic modulus of plastic concrete mixed with the sodium-based bentonite are about 1.5 times those with the calcium-based bentonite.The relative permeability coefficient of the former is smaller than that of the latter.Meanwhile,the dosage of the bentonite in the plastic concrete should be controlled between 20% and 40% and not exceed than 60%.The age of 90 days should be chosen as the standard curing age for the plastic concrete in mechanical property tests.