Effect of superplasticizers on the consistency and unconfined compressive strength of cemented paste backfills
Effect of superplasticizers on the consistency and unconfined compressive strength of cemented paste backfills
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DOI：
10.1016/j.conbuildmat.2018.05.288
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发表时间：
2018-08-30
影响因子：
7.4
通讯作者：
Yahia, Ammar
中科院分区：
文献类型：
--
作者：
Ouattara, Drissa;Belem, Tikou;Yahia, Ammar
本文评估了不同类型的高效减水剂（HRWR）对主要由固体质量含量为80%的尾矿T1（也用尾矿T2进行了一些测试）制备的胶结膏体充填料（CPB）的稠度（坍落度）和无侧限抗压强度（UCS）的影响。由80%的磨细粒化高炉矿渣和20%的通用硅酸盐水泥（GU）制成的混合胶结剂按三种不同比例制备：3.5%、4.5%和6%（按尾矿干质量计）。测试了六种高效减水剂类型：四种聚羧酸盐（PC1至PC4）、一种三聚氰胺磺酸盐（PMS）和一种萘磺酸盐（PNS）。测定了不同养护时间下新鲜CPB的坍落度值和硬化CPB试件的UCS。测试结果表明，无论高效减水剂类型如何，向CPB混合物中添加高效减水剂都能提高CPB的稠度和UCS。对于尾矿T1，为使坍落度值达到152（6英寸，这通常被认为是实现可泵送CPB的回填作业的下限），每种聚羧酸盐类型所需的最小用量为0.121%（按尾矿 + 胶结剂干质量计）。与萘磺酸盐和三聚氰胺磺酸盐类型的高效减水剂相比，聚羧酸盐类型的高效减水剂更有效地提高了CPB的稠度。然而，掺入所有类型高效减水剂的CPB在28天的UCS值相当。与对照CPB混合物（无高效减水剂）相比，添加高效减水剂的CPB在养护28天后UCS的增加幅度在21% - 29%之间，具体取决于胶结剂含量。从高效减水剂添加对水胶比变化的影响、固体含量和高效减水剂对UCS提高的贡献以及胶结剂消耗的潜在降低等方面对结果进行了讨论。（C）2018爱思唯尔有限公司。保留所有权利。
This paper assesses the effects of different types of high-range water reducer (HRWR) on the consistency (slump) and unconfined compressive strength (UCS) of cemented paste backfills (CPB) prepared mainly with tailings T1 at 80% solids mass content (a few tests were also conducted with tailings T2). A blended binder made of 80% ground granulated blast furnace slag and 20% GU (general use Portland cement) was prepared at three different proportions: 3.5%, 4.5%, and 6% (by dry mass of tailings). Six HRWR types were tested: four polycarboxylates (PC1 to PC4), a polymelamine sulfonate (PMS), and a polynaphtalene sulfonate (PNS). The slump values for fresh CPB and the UCS for the hardened CPB specimens were determined at different curing times. Test results showed that the addition of HRWR to CPB mixtures improved CPB consistency and UCS, regardless of HRWR type. For tailings T1, a minimal dosage of 0.121% (by dry mass of tailings + binder, for each PC type) was required to achieve a slump value of 152 (6 in., which is generally considered the lower limit in backfilling operations to achieve pumpable CPB). The PC-type HRWR more effectively increased CPB consistency compared to PNS- and PMS-type HRWR. However, UCS values at 28 days were comparable for CPB incorporating all HRWR types. The UCS increase after 28 days of curing for superplasticized CPB ranged from 21% to 29% compared to the control CPB mixture (without HRWR), depending on binder content. Results are discussed in terms of the impact of HRWR addition on the change in water-to-binder ratio, the contribution of solids content and HRWR to UCS improvement, and the potential reduction in binder consumption. (C) 2018 Elsevier Ltd. All rights reserved.