摘要:
为进一步研究在实际工程中半浸泡环境下,混凝土暴露在空气中的部分遭受更为严重的侵蚀破坏现象,对比吸附区与浸泡区的劣化规律差异,设计了五种轴压比(0, 0.2, 0.3, 0.4, 0.5)和两种浓度的硫酸盐溶液(5%、10%)耦合作用下混凝土长期半浸泡和干湿循环试验,并设置全浸泡作用下的混凝土作为对照,对比吸附区和浸泡区的劣化规律差异,分析不同轴压荷载与硫酸盐浓度对质量、相对动弹性模量和抗压强度的影响。试验结果表明:相同龄期时所有组合吸附区混凝土的劣化程度均大于浸泡区以及全浸泡作用下的混凝土;低应力比在侵蚀龄期前期具有一定的抑制劣化的作用,较高的应力比和较大的硫酸盐浓度对试件的劣化具有明显的促进作用;在0.2和0.3轴压比的轴压荷载与5%浓度硫酸盐耦合作用下试件在300 d龄期的相对动弹性模量下降了12%和7%,在轴压比为0.5的轴压荷载与5%、10%浓度硫酸盐组合下则分别下降至38%和42%。
Abstract:
In order to further study the semi-soaked environment in actual engineering, the part of concrete exposed to the air suffers from more serious erosion and damage, and the difference of the degradation law between the adsorption zone and the immersion zone, five kinds of stress ratio axial load and two concentrations of sulfate solution coupling under long-term semi-immersion and dry-wet cycle tests were designed, and the concrete under full immersion was set as a control. Comparing the difference of deterioration law between adsorption zone and immersion zone, analyzing the influence of different axial loads and sulfate concentration on mass, relative dynamic elastic modulus and compressive strength.The test results showed that the deterioration degree of concrete in all combined adsorption zones at the same age was greater than that in the immersion zone and full immersion, the low stress ratio had a certain effect of inhibiting deterioration on the early stage of erosion, and the higher stress ratio and larger sulfate concentration had a significant effect on the deterioration of the specimen. Under the coupling action of 0.2 and 0.3 ratio and 5% sulfate concentration, the relative dynamic elastic modulus of specimen in 300 d age decreased by 12% and 7%.The relative dynamic elastic modulus at 50% stress ratio and 5%, 10% sulfate coupling decreased to 38% and 42%.