抗裂材料对洞渣砂输水隧洞混凝土强度、变形和抗裂性能的影响

Influence of anti-cracking materials on strength,deformation and anti-cracking performance of tunnel slag sand water conveyance tunnel concrete

研究了KLJ-1型抗裂剂和轻烧氧化镁两种抗裂材料对洞渣砂输水隧洞混凝土强度、变形和抗裂性能的影响。使用水化量热仪和XRD分析了抗裂材料的作用机理,结合压汞仪(MIP)和扫描电镜(SEM)分析了抗裂剂对混凝土孔隙结构和微观形貌的影响。结果表明:洞渣砂混凝土的强度满足C25的设计要求,且两种抗裂材料提高了洞渣砂混凝土的强度。抗裂材料降低了混凝土的干燥收缩,标准养护下掺KLJ-1型抗裂剂混凝土无明显膨胀。抗裂材料提高了洞渣砂混凝土的抗裂性能,其中KLJ-1型抗裂剂减少了裂缝数量和面积,轻烧氧化镁降低了裂缝宽度和面积。KLJ-1型抗裂剂使水泥水化的C-S-H凝胶分布均匀,轻烧氧化镁水化使体积发生膨胀,两者都改善了混凝土孔结构,使混凝土更加密实。

It studies the influence of KLJ-1 anti-cracking agent and light burned MgO on the strength,deformation and crack resistance of concrete for tunnel slag sand water conveyance tunnel under standard curing and dry curing.The mechanism of crack resistant material was analyzed by hydration calorimeter and XRD analysis,and the effect of crack resistant agent on the pore structure and micro morphology of concrete was analyzed by mercury intrusion porosimetry(MIP)and scanning electron microscopy(SEM).The results show that the strength of tunnel slag sand concrete meets the design requirements of C25,and two kinds of crack resistant materials improve the strength of tunnel slag sand concrete.The anti-cracking material reduces the drying shrinkage of concrete,and the concrete mixed with KLJ-1 type anti-cracking agent has no obvious expansion under standard curing.The crack resistant materials have improved the crack resistance of tunnel slag sand concrete,among which KLJ-1 crack resistant agent has reduced the quantity and area of cracks,and light burned MgO has reduced the width and area of cracks.KLJ-1 anti-cracking agent makes the C-S-H gel of cement hydration evenly distributed,and the hydration oflight burned MgO makes the volume expand.Both of them improve the concrete pore structure and make the concrete more dense.