再生骨料原位强化研究

In-situ strengthening of recycled aggregate

通过模拟实验与微观结构分析研究了掺合料浆液包覆处理对新老混凝土复合试件水化硬化过程中模拟再生骨料界面以及本身强度的影响。结果表明,采用掺合料浆液进行表面处理可有效实现再生骨料的原位强化及其与水泥石之间的界面强化,其中硅粉浆液处理对模拟再生骨料原位强化与界面强化效果最佳,粉煤灰浆液处理对再生骨料的原位强化效果优于矿粉浆液,但对界面强化的效果却较弱,其原因与掺合料颗粒的粒径大小以及火山灰活性有关。

In-situ strengthening and interfacial strengthening of recycled aggregate in new-old concrete composite specimen were studied by simulation experiment and microstructure analysis. The simulated recycled aggregate was coated by using mineral admixture slurry before preparing the composite specimen. Shear strength of the composite specimen and compressive strength of the simulated recycled aggregate were tested after curing for 28 days. The results showed that surface treatment by using admixture slurry could effectively improve both the interfacial bond strength and the compressive strength of the simulated recycled aggregate itself. While coating with silica fume slurry, an optimum interfacial and in-situ strengthening effect was obtained for the simulated recycled aggregate. Surfacetreating by using fly ash slurry showed a better in-situ strengthening effect, but a less improvement in interfacial bond strength, than that with slag slurry, which was related to the particle size and pozzolanic reactivity of the admixture.