SCC力学性能及在结构工程中的应用

Mechanical properties of SCC and its application in structural engineering

采用粉煤灰替代部分水泥、调整粉煤灰与外加剂SP406掺量制备自密实混凝土(SCC)。通过塌落扩展度试验,研究了粉煤灰掺量、外加剂掺量分别对SCC流动性能的影响。通过立方体抗压试验、静力弹性模量试验以及轴心抗压试验研究了粉煤灰、外加剂掺量对自密实混凝土力学性能的影响并优选出了最佳掺量组。通过SEM分析了优选掺量SCC在不同龄期下的作用机理。结果表明:SCC的流动性随粉煤灰掺量的增加而减小,随外加剂掺量增加而增加。而混凝土的力学性能则随着粉煤灰掺量的增加而出现先增大后减小的现象。外加剂掺量提高则会提高混凝土的早期强度,随着龄期的延长影响会逐渐变小。最后将试验确定的16%粉煤灰、3.2%外加剂SCC应用于实体工程,通过质量检验及经济分析发现制备的SCC外观、强度、经济效益均满足施工技术要求。

Self-Compacting Concrete(SCC) was prepared by replacing part of the cement with fly ash and adjusting the admixture SP406. The effects of fly ash and admixture dosing on the flow properties of SCC were investigated through the collapse expansion test. The effects of fly ash and admixtures on the mechanical properties of SCC were investigated by cubic compressive strength test, static compressive modulus test and axial compressive strength test, and the optimum admixture group was selected. The mechanism of the selected SCC admixture at different ages was analyzed by SEM.The results showed that the fluidity of SCC decreased with the increase of fly ash admixture and increased with the increase of admixture admixture. The mechanical properties of concrete increased and then decreased with the increase of fly ash admixture. The increase of admixture will improve the early strength of concrete, and the effect will become smaller with the extension of the age. Finally, the test determined 16% fly ash, 3.2% additive SCC applied to the physical project, through quality inspection and economic analysis found that the prepared SCC appearance, strength, economic benefits are to meet the construction technology requirements.