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本文主要研究了不同养护温度下混凝土的强度及抗氯离子渗透性。通过测定出标准养护、3℃养护、-3℃养护以及变温(5→-3℃)条件下养护混凝土不同龄期的抗压强度,分析了低、负温养护下混凝土强度增长规律并与标准养护下混凝土强度进行比对得出:养护温度是影响混凝土强度的重要因素,前期养护温度越低,28 d的抗压强度越低;低、负温下养护时,混凝土的强度早期增长比标养下慢,后期增长比标养下快;变温养护下,3 d前强度增长较快,3 d后其强度的增长与-3℃养护的混凝土差不多。同时采用直流电量法对这四种养护情况下56 d时混凝土进行了抗氯离子渗透性研究,试验结果表明:养护温度越低,混凝土的抗氯离子渗透性越差。
This paper mainly studied the concrete strength and resistance to chloride ion permeability at different curing temperatures. The compressive strength of concrete cured at different ages under the conditions of standard curing, 3 ℃ curing, -3 ℃ curing and variable temperature (5 → -3 ℃) was analyzed. The law of strength growth of concrete under the condition of low and negative temperature was analyzed and compared with the standard The results show that the curing temperature is an important factor affecting the strength of concrete. The lower the curing temperature is, the lower the compressive strength at 28 d. The strength of concrete at early and lower temperature is higher than the standard Under slow temperature maintenance, the growth in the later stage was faster than that in the standard stage. Under the condition of variable temperature curing, the intensity increased rapidly 3 days before, and its strength increased almost at 3 ℃ after 3 days. At the same time, the DC resistance method was used to study the resistance to chloride ion permeability of concrete during the 56 days under the four curing conditions. The results show that the lower the curing temperature is, the worse the chloride resistance of concrete is.