草浆黑液的化学改性和作为混凝土减水剂的应用

Chemical modification of straw pulping black liquor and used as water reducer for concrete

采用催化氧化再磺化工艺制备了水溶性草浆黑液木质素磺酸盐(SBT-LSN)混凝土减水剂。混凝土试验结果表明,经磺化改性后的产品分散性能得到明显改善,在0.25%掺量下,混凝土减水率达11.4%,含气量为4%,有一定的缓凝作用;对混凝土抗压强度有较大的提高,3d和28d抗压强度比分别达125%和110%,对混凝土早期强度的改善更明显。其适宜的掺量范围为水泥含量的0.1%～0.5%,适合于配制C40(及以下)中低强度混凝土。

Water soluble straw pulping black liquor＇s lignosulfonate （SBT-LSN） water reducer for concrete was prepared through catalytic oxidation and sulfonation reaction. Concrete performance testing results showed that by sulfonate modification the dispersion of sulfonated product was improved obviously and at the addition of 0.25% water reducer, water reduction of the concrete is up to 11.4%, air content of 4% that has a certain function of delayed coagulation. The compression strength of concrete is greatly improved that is up to 125% at 3 days and up to 110% at 28 days. It has more obvious improvement to the early strength of concrete. This water reducer is more effective at dosages of 0.1%-0.5% of the cement content,and it is fit for confecting normal and lowstrength concrete C40 （and〈C40）.