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对全级配混凝土试件及其湿筛混凝土试件分别进行0、50、100、150、200、250和300次快速冻融循环试验。观察冻融后试件外观的变化情况,测定冻融循环后全级配混凝土和湿筛混凝土的抗压强度与抗拉强度,讨论了冻融循环对抗压强度、抗拉强度及其应力应变关系的影响。试验发现,冻融循环后全级配混凝土的外观破损情况较湿筛混凝土严重得多。试验结果表明,随冻融次数增加,全级配混凝土与湿筛混凝土的抗压强度与抗拉强度均明显降低,但全级配混凝土的降低值较湿筛混凝土的降低值大,特别是抗拉强度,降低幅度更大。两种混凝土单轴压应力应变曲线峰值应力点随冻融循环次数增加逐渐向右下方偏移,曲线形状变得扁平,而其单轴拉应力应变曲线峰值应力点随冻融循环次数增加逐渐向左下方移动,曲线变短。通过对试验结果的分析,建立了全级配混凝土和湿筛混凝土之间单轴压及单轴拉关系的数学公式,可以为寒冷地区大坝、海洋平台等的设计、维修、维护及其寿命预测等提供理论依据。
The full-scale concrete specimens and their wet-sieved concrete specimens were subjected to 0, 50, 100, 150, 200, 250 and 300 rapid freeze-thaw cycles respectively. The change of appearance after freezing and thawing was observed. The compressive strength and tensile strength of full grade concrete and wet sieve concrete after freeze-thaw cycle were measured. The compressive strength, tensile strength and stress-strain The impact of the relationship. The test found that the whole graded concrete freeze-thaw cycle appearance damage is much more serious than the wet-sieve concrete. The experimental results show that with the increase of the number of freeze-thaw cycles, the compressive strength and tensile strength of concrete with full-grade concrete and wet-screened concrete are all obviously reduced, but the value of full-grade concrete is lower than that of wet-sieved concrete, Tensile strength, reduce the greater extent. The uniaxial compressive stress and strain curves of the two concretes peak stress points gradually shift to the lower right and lower with the increase of the number of freeze-thaw cycles, the shape of the curve becomes flat, while the peak stress point of the uniaxial tensile stress-strain curve gradually increases with the increase of the number of freeze-thaw cycles Left bottom of the move, the curve becomes shorter. Through the analysis of test results, the mathematical formulas of uniaxial tension and uniaxial tension between concrete with full scale and wet-screened concrete are established, which can be used to design, repair, maintain and predict the life of dams and offshore platforms in cold areas Provide a theoretical basis.