掺粉煤灰混凝土强度劣化试验研究

为研究掺粉煤灰混凝土的抗压强度劣化规律，以碎石、水泥、粉煤灰、中砂与自来水为原材料，制备掺粉煤灰混凝土试件。在碳化与干湿循环等环境作用下，利用万能压力试验机，展开试件强度劣化试验。试验结果表明：粉煤灰掺量未超过30%(包含30%)时，试件抗压强度未出现劣化现象；粉煤灰掺量超过30%时，粉煤灰掺量越多，试件抗压强度劣化程度越大。龄期延长，各试件抗压强度均有所提升；增加粉煤灰掺量，会提升试件劈拉强度的劣化程度；延长龄期，会减缓试件劈拉强度的劣化速度。增加水胶比含量，导致试件劈拉、抗压强度劣化程度提升；碳化作用下，试件抗压及劈拉强度有所提升，碳化时间为13 d时，试件抗压及劈拉强度达到峰值；干湿循环作用下，试件的抗压及劈拉强度均会出现劣化情况，粉煤灰掺量为30%时，试件的抗压及劈拉强度均值相对较高。

Strength degradation test of concrete mixed with fly ash

In order to study the deterioration law of compressive strength of fly ash mixed concrete, fly ash mixed concrete specimens were prepared with crushed stone, cement, fly ash, medium sand and tap water as raw materials. Under the action of carbonization and dry wet cycle, the strength deterioration test of the specimen is carried out by using the universal pressure testing machine. The test results show that when the content of fly ash does not exceed 30% (including 30%), the compressive strength of the specimen does not deteriorate; When the content of fly ash exceeds 30%, the more the content of fly ash, the greater the deterioration of compressive strength. The compressive strength of each specimen increased with the extension of age; Increasing the content of fly ash will improve the deterioration of splitting tensile strength; Prolonging the age will slow down the deterioration rate of splitting tensile strength. Increasing the content of water binder ratio leads to the improvement of splitting tensile and compressive strength deterioration of the specimen; Under carbonization, the compressive and splitting tensile strength of the specimen are improved. When the carbonization time is 13 days, the compressive and splitting tensile strength of the specimen reach the peak value; Under the action of dry wet cycle, the compressive and splitting tensile strength of the specimen will deteriorate. When the content of fly ash is 30%, the average compressive and splitting tensile strength of the specimen is relatively high.