胶结人工砂石筑坝材料性能研究

胶凝砂砾石为一种环境友好材料,在我国筑坝实践中得到了大量应用。由于胶凝砂砾石坝主要应用于河床砂砾石料丰富的地区,使得胶凝砂砾石的推广受到一定的局限,对于缺少河床天然砂砾石工程,可用人工砂石来修建胶结人工砂石坝。研究了骨料破碎工艺、配合比设计中水胶比、水泥用量、粉煤灰掺量、砂率等参数的选取对材料性能的影响,并进行了坝型方案比较。研究结果表明:(1)人工砂石骨料的简易破碎方式,即锤式破碎机单机破碎不筛分,一次破碎后直接使用;(2)人工砂石强度较高,单机破碎后级配相对稳定,配置强度均匀,耐久性能均优于采用河床天然砂砾石配置的胶凝砂砾石;(3)云南那恒水库在方案论证阶段,进行了胶结人工砂石坝的技术经济比较,胶结人工砂石坝型投资较碾压混凝土坝节省约10%。胶结人工砂石坝拓展了筑坝材料的利用范围,对于无天然河床砂砾的地方筑坝提供了一种新的坝型选择。

Proportion design and property of cemented artificial sand and gravel material

Cemented sand, Gravel and Rock (CSGR) has been developed as an environmentally friendly material in the practice of dam construction in China. Because the CSGR dam was mainly used in the river bed which was rich in natural sand and gravel, the popularization of the CSGR material was limited to a certain degree. For the river bed that lacks natural sand and gravel, artificial sand and gravel can be used to build the Cemented Artificial Sand and Gravel (CASR) dam. The parameters such as water binder ratio, cement dosage, fly ash content and sand rate are studied in the paper, the durability of materials and the design principle of dam section are discussed,and the comparison of dam type schemes is carried out. This research shows:(1) The simple crushing way of artificial sand aggregate, that is, the gravel could directly be smashed by single machine after one break in the hammer crusher. (2) Because the strength of natural aggregate was high,the grading was relatively stable. The intensity of the CASR material was quite uniform. The frost resistance property and impermeability of the CASR was higher than cemented natural sand, gravel and rock material. (3) After the comparison of CASR dam type in the permanent project of Naheng reservoir in Yunnan Province, it saved 10% investment compared with RCC Dam. The CASR dam type has expanded the alternative of damming materials, and provides a new type of dam for the dam construction on the river that has to natural sand and gravel.