摘要
系统研究废弃黏土砖100%替代天然骨料制作混凝土的抗压强度。采用正交方法设计试验,抗压强度试验结果的极差和方差分析表明:石灰有助于提高再生混凝土早期强度,并且可作为黏土砖粉的活性激发剂,但其对最终强度不利,最佳掺量为不超过3%;水泥对再生混凝土强度影响显著,强度会随水泥掺量增加而增长,从低碳环保角度建议水泥最佳掺量为25%;高水灰比有助于加快早强强度的产生,且影响显著,但再生混凝土最终强度与水灰比成反比,水灰比不宜超过0.5;废弃黏土砖100%替代天然骨料制作混凝土,强度可以达到设计值的50%,适用于次要结构或非承重构件的制作。其与天然骨料混凝土强度的差异可以从水化产物的微观形态角度阐释。
The compressive strength of recycled concrete is systematically studied which the aggregates are 100%substituted by waste clay brick.The orthogonal test method is adopted,range and variance methods are used to analyze the results of compressive strength.The results show that the lime helps to improve the early strength of recycled concrete,and it can be used as active activator of clay brick powder,lime has an adverse effect on the final strength of recycled concrete,so the optimal dosage should not exceed 3%.The cement has a significant effect on the strength of recycled concrete.The more the cement content,the higher the compressive strength,from the perspective of energy conservation,the optimal cement content is 25%.The early compressive strength of high water-cement ratio can be improved obviously,but the final strength is inversely proportional to the water-cement ratio,so the W/C ratio should not exceed 0.5.The abandoned clay brick can replace the natural aggregate 100%,and the strength of recycled concrete can reach half of the design value,apply to the subordination structures or non-load-bearing elements.The difference of strength between natural aggregate concrete and natural recycled concrete can be revealed by the microscopic morphology of the hydration products.
作者
张璐
李海洲
任皎龙
ZHANG Lu;LI Haizhou;REN Jiaolong(School of Civil and Architectural Engineering,Shandong University of Technology,Zibo 255000,China;Resources and Environmental Engineering,Shandong University of Technology,Zibo 255000,China;School of Science and Engineering,Shandong University,Jinan 250100,China)
出处
《混凝土》
CAS
北大核心
2020年第11期79-82,88,共5页
Concrete
基金
中国博士后科学基金(2019M662437)
国家自然科学基金青年基金(51808326)。
关键词
100%再生骨料
废弃黏土砖
抗压强度
微观形态
100%recycled concrete
waste clay brick
compressive strength
micro morphology
