C-S-H/PCE凝胶对掺磷渣水泥的低温促凝早强性能研究

探讨C-S-H/PCE凝胶对掺磷渣硅酸盐水泥的低温促凝早强性能的影响，并通过上清液pH值、Ca2+浓度和化学结合水量分析其对水化的影响机理。低温下（8 ℃） C-S-H/PCE凝胶能有效缩短混凝土终凝时间，并提高早期强度，当掺量5%时，混凝土终凝时间缩短近6 h，16 h、24 h和3 d抗压强度比分别为160%、150%和110%，且不影响2.5 h混凝土工作性能。C-S-H/PCE凝胶能使低温下掺磷渣硅酸盐水泥浆体处于高pH状态，加速早期水泥矿相离子溶解，提高Ca2+过饱和度，加速后期析晶过程，提高化学结合水量，从而促进掺磷渣硅酸盐水泥的水化，实现低温促凝早强。

Effect of C-S-H/PCE gel on performance of promoting setting-time and early-strength of Portland cement mixed with phosphorus slag at low temperature

The effect of C-S-H/PCE gel on performance of promoting setting-time and early-strength of Portland cement which mixed with phosphorus slag at low temperature was discussed in this paper,and the mechanism of its influence on hydration was analyzed through the pH value of supernatant,Ca²⁺concentration and chemically bound water content.At low-temperature(8 ℃),C-S-H/PCE gel can effectively shorten the final-setting time of concrete and improve the early strength.When the dosage was 5%,the final-setting time of concrete was shortened by nearly 6 h,and the compressive strength ratios of 16 h,24 h and 3 d were 160%,150%and 110%respectively,with which the working performance of concrete at 2.5 h is not affected.C-S-H/PCE gel can make the Portland cement which mixed with phosphorus slag slurry in a high pH state at low temperature,accelerate the ion dissolution of the early cement mineral phase,increase the Ca²⁺ supersaturation,accelerate the crystallization process at the later stage,and increase the chemically bound water content,thus promoting the hydration of Portland cement which mixed with phosphorus slag and promoting setting-time and early-strength.