造纸废液接枝改性减水剂对混凝土性能的影响

Influence of Water Reducers Prepared by Grafting Pulp Wastes on Concrete Performances

本文系统对比研究了一种造纸废液接枝萘磺酸盐单体制备的新型高效减水剂(LPCN)与传统木质素磺酸钙普通减水剂(CL)对C40混凝土多种性能的影响。结果表明,LPCN能够大幅改善混凝土拌合物的初始流动性,但泌水率较高,具有弱于木质素磺酸钙的引气和缓凝作用;可使混凝土28 d抗压强度和抗折强度提高15%,能抑制混凝土后期收缩,使其一维和二维碳化深度降低20%以上,并延缓了冻融循环过程中混凝土损伤劣化。

A novel superplasticizer monomers onto of conventional intermediates extracted calcium lignosulfonate （LPCN） was copolymerized by grafting naphthalenesulfonate from pulp wastes. Comparative studies were made and influences water reducer （CL）and LPCN on multi performances of C40 concretes were systemically investigated. Results show that LPCN can endow concretes with better initial slump but higher bleeding rate, moderately set-retarding and air entraining effects, which were poorer than those of concretes with CL. It was found that mechanical properties of concrete with LPCN were greatly enhanced and carbonization depths of C40 concretes in 1D and 2D were both decreased by 20% more. Deteriorations of concretes during freezing and thawing cycles were also delayed.