木质素系高性能引气减水剂GCL1-D的性能和作用机理研究

Study on the performance and mechanism of AE superplasticizer GCL1-D modified by lignosulphonate

随着高性能混凝土的发展,研制开发性能优良、对混凝土强度和耐久性效果好的高性能引气减水剂已成为混凝土工程亟待解决的问题。试验研究了木质素系高性能引气减水剂GCL1-D对砂浆及混凝土应用性能的影响,并初步探索其作用机理。结果表明,GCL1-D具有优良起泡性能,溶液最大泡径仅1.0mm。掺加0.4%GCL1-D的混凝土减水率为18.1%,3d和28d混凝土强度比分别达161%和145%,28d砂浆抗渗比达到418%。掺加GCL1-D硬化砂浆的3d和28d开口孔隙率较空白砂浆的降低了28%和21%,最可几孔径仅为空白砂浆的26%,且孔径小于0.015mm的孔含量最多,孔径大于0.065mm的孔相对较少,最大孔径为1.05mm。GCL1-D在砂浆中引入的气泡细腻,增强了减水分散作用,微细孔阻断了水渗透通道,提高了硬化砂浆和混凝土的抗渗性能和抗压强度。

Nowadays high performance concrete（HPC ）that exhibits high strength, excellent workability and durability is widely used in construction and the performance of air entraining （ AE ）superplasticizer used in concrete is required to be improved. In this paper the performance and mechanism of AE superplasticizer GCLI-D, which is developed by modification of lignosulphonate, is studied. Results show that GCLl-D has good foaming performance and the bubbles with a maximum diameter of 1.0mm are fine and stable. When added 0.4% GCLI-D, the water reducing ratio of concrete is 18.1% as well as the compressive strength ratio of 3 day and 28 day of harden concrete is 161% and 145%. The 28 days impermeability pressure ratio of harden mortar blended with GCLl-D reaches 418%. Further studies show that the open porosity of 3 days and 28 days of harden mortar added GCLl-D is 28% and 21%, which is lower than that of blank. Harden mortar added GCLl-D has more pores smaller than 0.015mm, fewer pores larger than 0.065ram, and the largest pore diameter is 1.05mm, the most probable pore diameter is only 26% of that of blank. All these help to improve the compressive strength and impermeability of mortar and concrete.