摘要
高强轻骨料混凝土(HSLWC)的收缩性能是预应力HSLWC结构设计的重要参数.采用低吸水率(2.5%)轻骨料、28d抗压强度为55～65MPa的HSLWC,其180d龄期时的收缩率值范围是5.2×10-4～7.7×10-4,且180d龄期之内的收缩率统计值比JGJ51—2002规程的限值大0.7×10-4～2.8×10-4,这当中主要的差异发生在早期.HSLWC的收缩随轻骨料含水率和绝干密度的增大、胶凝材料用量的减少而减小.采用混合骨料(高、低吸水率轻骨料混合或轻骨料与普通密度粗骨料混合)、添加减缩剂,将有助于减小HSLWC的收缩.
Shrinkage of high strength lightweight aggregate concrete (HSLWC) is an important parameter for the design of prestressed HSLWC structures. HSLWC with a 28 d compressive strength of 55～65 MPa, which was prepared with lightweight aggregate with a low water-absorption, had a 180 d shrinkage of 5.2×10^(-4)～7.7×10^(-4). The shrinkage of such HSLWC within 180 d was 0.7×10^(-4)～2.8×10^(-4) larger than the recommended values of JGJ 51—2002, the Chinese national technical specifications for lightweight aggregate concrete (LWC). Most of the difference happened at early ages. Shrinkage of HSLWC increases with the reduction of the density and moisture content of lightweight aggregate, and the increase of binder content. It is helpful to reduce shrinkage of HSLWC by using mixed coarse lightweight aggregates with high and low moisture content or lightweight aggregate mixed with normal density aggregate, and adding shrinkage-reducing agent.
出处
《建筑材料学报》
EI
CAS
CSCD
2004年第2期138-144,共7页
Journal of Building Materials
基金
云南省科技厅2001年省院省校科技合作项目(2001BBBCA15A010)
交通部2002年西部开发交通科技项目(2002 318 767 31)
关键词
高强轻骨料混凝土
收缩
含水率
混合骨料
减缩剂
high strength lightweight aggregate concrete
shrinkage
moisture content
mixed aggregate
shrinkage-reducing agent
