砂浆扩展度法评价水泥与减水剂相容性

Evaluation of compatibility of cement and water reducer by mortar dispersion method

正确可靠地评价水泥与减水剂相容性的方法,对水泥、减水剂的生产方和使用方都至关重要。提出使用砂浆扩展度法评价水泥与减水剂相容性。通过试验条件的多因素试验,确定了该方法的关键技术参数:水灰比为0.40,灰砂比为600∶1 350。试验结果表明,该方法重复性<5mm,再现性<8mm。初始砂浆扩展度和经时砂浆扩展度分别与混凝土初始扩展度和经时扩展度具有良好的相关性,可替代混凝土来评价水泥与减水剂相容性。由于采用了ISO标准砂,若固定用一种减水剂,可评价水泥;固定水泥,可评价减水剂。

Evaluation method of compatibility of cement and water reducer was very important to manufacturer and user of cement and water reducer. This paper presents the mortar dispersion method for evaluation of compatibility of cement and water reducer. The key technical parameters of mortar dispersion method were determined by multi-factor experiments, the water-cement ratio was 0.40,and the cement-sand ratio was 600：1350. The results indicated that the repeatability was less than 5mm and reproducibility was less than 8mm. The initial slump flow of mortar was well correlative to the initial slump flow of concrete, and the fluidity loss of mortar was well correlative to that of concrete, so the mortar could replace concrete to evaluate the compatibility of cement and water reducer. The effect of cement on compatibility of cement and water reducer could be evaluated by mortar dispersion method when using fixed water reducer, and the effect of water reducer on compatibility of cement and water reducer could be evaluated by mortar dispersion method when using fixed cement.