基于巴氏芽孢杆菌矿化沉积的再生骨料改性试验研究

Experimental study on modification of recycled aggregates based on Sporosarcina pasteurii′s mineralization

再生混凝土能够有效地实现对废弃混凝土的再利用,但由于骨料的自身缺陷,再生骨料会一定程度地降低混凝土的力学性能和耐久性能。基于一种脲酶菌巴氏芽孢杆菌矿化沉积特性对再生骨料进行改性处理,主要考察改性时间对再生骨料吸水率、质量变化率、表观密度和压碎指标等物理力学性能指标的影响。试验结果表明,巴氏芽孢杆菌矿化沉积能够有效提高再生骨料的质量和表观密度,并降低再生骨料的吸水率和压碎指标;改性后再生骨料质量增长率可达3%,吸水率可由未改性的4%降至2.14%。研究结果可为基于微生物矿化沉积的再生骨料改性研究提供参考。

Recycled concrete can effectively realize the reuse of waste concrete,while it may reduce the mechanical properties and durability of concrete to a certain extent because of its defects.A modification method of recycledaggregate based on the mineralization characteristics of Sporosarcina pasteurii was presented.The effect of modification time on the physical and mechanical properties of recycled aggregate such as water absorption,mass variation,apparent density and crush value index were investigated.It shows that the mineralization of Bacillus pasteuria could effectively increase the mass and apparent density of recycled aggregate,and reduce the water absorption and crush value index of recycled aggregates.Moreover,the mass of the recycled aggregates withmodification increased 3%compared to the aggregates without modification.The water absorptions of recycled aggregates with modification andwithout modification were 2.14%and 4%respectively.The results of this study were expected to be useful for the modification research of recycled aggregates based on microbial mineralization.