混凝土的裂缝与控制

Concrete crack and control

在分析混凝土开裂的危害和产生原因的基础上,提出裂缝控制新技术。采用双亲性单分子膜,减少混凝土早期的水分蒸发,抑制混凝土早期因失水太快而产生的塑性收缩裂缝;采用减水与减缩共同作用,控制混凝土壳体及薄壁结构的早期开裂;采用调控水泥水化过程中的放热量,提高大体积混凝土的温控能力;采用遥爪聚合型增韧剂,增加混凝土的韧性,减少混凝土的脆性开裂。

Concrete cracking is a very popular problem throughout the civil engineering construction. In this paper, the harms and causes of concrete crack were analyzed first. Thereafter, new strategies for control cracking were proposed. An amphiphilic monolayer was introduced to reduce the evaporation rate and inhibit plastic shrinkage cracking of early-age concrete. A new chemical admixture with combined effect of water reduc- tion and shrinkage reduction was developed for decreasing cracking risk of shell structure as well as thin-walled structure. Based on the regulation of early age hydration of cement, a new technology was introduced for impro- ving temperature control effect of mass concrete. At last, a telechelic toughening material was also recommended to improve the toughness of concrete and thus reduce its brittleness.