不同养护温度下混凝土的强度及抗氯离子渗透性试验研究

Experimental Study on Concrete Strength and Resistance to Chloride Ion Permeability under Different Curing Temperature

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 studies the strength and resistance to chloride ion permeability of concrete under different curing temperatures. By measuring the compressive strength of concrete at different ages cured under the standard curing condition, 3 ℃ curing, - 3 ℃ curing and variable temperature （ 5 ℃ → - 3 ℃ ） curing, analysis the strength growing rules of concrete cured under low and negative temperature, compared to the concrete cured under the standard curing condition finds out that, curing temperature is an important factor of the concrete＇s strength, the lower the pre-curing temperature, the lower the compressive strength of concrete at 28 d, while concrete cured under low and negative temperature, its early strength increase slower than the concrete cured under the standard curing condition, its later strength increase faster than it, while concrete cured under variable temperature, its strength increase faster before 3 d, and its strength increase nearly to the concrete cured under - 3 ℃ after 3 d. DC method was used to study the resistance to chloride ion permeability of concrete cured under four different temperatures at 56 d, the results show that the lower the curing temperature, the worse the resistance to chloride ion permeability of concrete.