混合骨料在BEJ拱坝混凝土中的应用研究  

Application of mixed aggregate in concrete of BEJ arch dam

作　　者：罗纬邦[1] 

机构地区：[1]新疆水利水电勘测设计研究院,新疆乌鲁木齐830000

出　　处：《人民长江》2017年第19期102-105,共4页Yangtze River

摘　　要：在某些情况下,工程受客观条件限制而无法选择满足现场混凝土配置需要的骨料,为了改善骨料级配,会采用人工和天然混合骨料的施工方案。以新疆BEJ大坝为例,通过试验对混合骨料混凝土的各项性能指标进行比较分析。结果表明:使用混合骨料的大坝混凝土和易性较好,坍落度和含气量均在控制范围内;各个强度等级混凝土90 d龄期抗压强度均能达到设计强度等级,混凝土早期强度增长较快;早期弹性模量和极限拉伸值随着粉煤灰掺量的增加而降低,但后期增加;混凝土耐久性能也均能满足设计要求,质量损失随粉煤灰掺量增加而增大,煤灰掺量对抗渗性能影响较小。Aggregate accounts for about 80% of a concrete dam by volume,so the effects of aggregate properties on the concrete performance could not be neglected. Due to the restricted practical conditions of BEJ project,the natural aggregate could not meet the needs of the concrete＇s mix design,so the solution of artificial and natural mixed aggregate was adopted to improve the performance of aggregate gradation. Based on the comparison analysis of the performance of BEJ dam,it shows that the workability of mixed aggregate concrete are better,the slump and air content are within the control. The compressive strength of all grades concrete at the age of 90 d can reach the designed strength grade,and the early strength of concrete increase rapidly; the elastic modulus and ultimate tensile strength of concrete at early age reduce with the increase of fly ash,but increase at later ages; the durability also could meet the designed requirements. The mass loss of concrete increases with increase of fly ash,but the content of fly ash has little effect on the impermeability.

关 键 词：混合骨料 力学性能 变形性能 耐久性能 

分 类 号：TV431[水利工程—水工结构工程]