戈壁地区不同养护方式下混凝土桥墩回弹强度与试块强度试验研究

为了研究戈壁地区不同养护方式下混凝土桥墩的回弹强度与试块强度的变化规律,首先对原材料的各项性能进行了检测与分析,然后通过对戈壁地区不同养护方式(标准养护、大气养护、土工布包裹养护、橡塑板包裹养护)下混凝土桥墩及同条件试块在不同龄期(3,5,7,14,28,56 d)时的强度进行了测试和分析,将所得的混凝土桥墩回弹强度及试块强度的发展规律进行了公式拟合和验证。结果表明:①按照大气养护、土工布包裹养护、橡塑板包裹养护、标准养护的顺序,混凝土抗压强度、抗拉强度、拉压比逐渐增大;②戈壁地区不同养护方式下,混凝土桥墩的回弹强度小于试块强度,两者的差值在3~9 MPa之间,随着龄期的增加两者的差值逐渐减小;③戈壁地区混凝土养护方式保温保湿效果越好,回弹强度与试块强度之间的差值就越小;④提出了戈壁地区不同养护方式下混凝土回弹强度及试块强度的计算公式,所得公式经验证误差较小,可以作为强度计算的参考。

Rebound Strength and Test Block Strength of Concrete Bridge Pier under Different Curing Methods in Gobi Region

To obtain the variation law of the rebound strength of concrete pier and the strength of test block under different curing methods in Gobi region, we tested and analyzed the properties of the raw materials firstly. In subsequence, we tested the strength of concrete piers and test blocks cured by different methods (standard curing, air curing, geotextile maintenance, and rubber-plastic board maintenance) in Gobi region at different ages (3 d, 5 d, 7 d, 14 d, 28 d, and 56 d). Formula fitting and verification results of rebound strength and test block strength show that: (1) The compressive strength, tensile strength, and ratio of tensile strength to compressive strength increased gradually following the order of air curing, geotextile maintenance, rubber-plastic board maintenance, and standard curing. (2) The rebound strength of concrete pier under different curing conditions in Gobi region is smaller than the strength of test block, with the difference between 3-9 MPa, which reduces along with the increase of age. (3) When the thermal insulation effect of curing method improves, the difference between rebound strength and block strength of concrete in Gobi region shrinks. (4) The calculation formulae of concrete's rebound strength under different curing conditions in Gobi region and the strength of test block are proposed and verified to be of small error, hence could be used as reference for strength calculation.