大掺量掺合料对海工混凝土耐久性的影响及工程实证

Influence and construction verification on the durability of marine concrete with large amount of admixtures

采用粉煤灰、矿粉大掺量单掺及复掺,研究矿物掺合料、阻锈剂对海工混凝土强度、耐久性的影响,并进行海洋工程应用验证。结果表明:按照40%比例复掺矿物掺合料对混凝土强度影响较小,复掺15%粉煤灰+25%矿粉时混凝土的84 d抗氯离子渗透系数最小;阻锈剂掺入对混凝土抗压强度没有明显影响;阻锈剂掺量为3%~7%时,168 h腐蚀电流小于150μA;海工混凝土现场留样84 d氯离子扩散系数最大值为1.30×10^(-12) m^(2)/s,保障了小干至长峙跨海通道混凝土的耐久性。

The influence of mineral admixtures and rust inhibitors on the strength and durability of marine concrete was studied by using single and compound admixtures of large amount of fly ash and mineral powder,and the application verification of marine engineering is carried out.The research in this paper shows that double addition of mineral admixtures with a content of 40%has little effect on the strength of concrete,and the lowest 84 d chloride ion diffusion coefficient concrete is achieved by adding 15%fly ash and 25%slag powder.The addition of rust inhibitor has no obvious effect on the compressive strength of concrete,and the corrosion current values of 168 h with the dosage exceeds 3%are lower than 150μA.The maximum value of 84-day chloride ion diffusion coefficient of marine concrete on-site sample is 1.3×10^(-12) m^(2)/s,which ensures the durability of the cross-sea passage from Xiaogan to Changzhi.