【作者】 杨小龙；

【导师】 郑娟荣；

【作者基本信息】 郑州大学 ， 结构工程， 2013， 硕士

【摘要】 本论文主要研究了利用尾矿集料配制绿色高性能混凝土的配合比设计方法及其应用。根据集料最大堆积密度原理,提出固定砂石体积参数并结合绝对体积法计算尾矿集料高性能混凝土配合比的设计方法。试验研究了混凝土各项性能(和易性、强度、耐久性)与配合比设计中各参数(砂石体积参数和水胶比等)的关系；针对混凝土的特殊性能要求,对本文提出的配合比设计方法进行了验证,结果是有效的。通过对尾矿集料混凝土各项性能的研究得出以下结论：当配制混凝土强度要求为60～80MPa时,1m3混凝土中粗骨料堆积体积为0.75m3～0.80m3,细骨料掺量(以砂浆体积计)43%～47%,通过外加剂调整可以配制的混凝土和易性从振动成型到泵送施工；当混凝土强度要求达到80MPa并具有坍落度要求时,除了粗细骨料要有致密堆积、降低水胶比外,胶凝材料的颗粒级配、化学活性匹配和热养护是有效途径,过多增加外加剂使混凝土泌水,对混凝土各项性能均不利。尾矿集料绿色高性能混凝土的水胶比在0.40～0.30,对应的混凝土28d抗压强度为55MPa～80MPa；在相同水胶比的条件下,混凝土28d抗压强度随浆体体积减少(即粗细骨料总体积增大)而增大,但减少到一定值后(外加剂超量加入)又下降,结果表明骨料表面浆体厚度或水泥浆粘度有一个最佳值。通过对水胶比与强度之间关系的研究,结合JGJ55-2011《普通混凝土配合比设计规范》得出适宜配制尾矿混凝土的回归系数,αa、αb分别为0.811和0.799。。按本论文提出的配合比设计方法,利用全尾砂细砂和废矿石粗细骨料完全代替天然砂石骨料、矿渣微粉和粉煤灰及缓凝型聚羧酸高效减水剂配制的尾矿集料混凝土,每立方米水泥用量仅330kg/m3,坍落度220mm,7d强度达到了36MPa,28d强度达到62MPa,满足工程设计要求。与目前工厂具有相同原材料的地铁管片混凝土相比,按本论文提出的配合比设计方法所配制的地铁管片混凝土具有浆体体积用量更小,力学性能更高、耐久性好、性价比高等性能。更多还原

【Abstract】 This thesis mainly studied mix proportion design method of preparation Green High Performance Concrete by use the tailings aggregate and its application. According to the principle of the maximum aggregate packing density, Proposed a design method of calculate mix ratio of tailings aggregate high-performance concrete by the fixed gravel volume parameters and combined with the absolute volume method. Experimental study on the relationship between the performance of concrete (workability, strength, durability) and the parameters(the parameters of gravel volume and water-cement ratio, etc.) in the design. According to the special performance requirements of concrete, the mixture ratio design method proposed in this paper are verified, the results are effective.Through the study of performance of tailings aggregate concrete obtain the following conclusions:When preparing the concrete strength requirements of60～80MPa,1m3concrete the bulk volume of coarse aggregate of0.75m3～0.80m3, fine aggregate content is(with mortar volume count)43%～47%, adjustment through admixture the concrete workability can be made from vibration molding to pumping construction; when the concrete strength requirements up to80MPa and the slump is required, besides aggregate should have dense accumulation and reduce the water cement ratio, grain size distribution of cementitious materials, chemical activity matching and thermal curing are effective ways, to excessive increase admixture made the concrete bleeding, and are detrimental to the performance of the concrete.Green high performance concrete of tailings aggregate water cement ratio of0.40～0.30, corresponding to the28d compressive strength of concrete is55MPa～80MPa; under the conditions of the same water-cement ratio,28d compressive strength of concrete increases with slurry volume decreased(Which the total volume of the coarse and fine aggregate increasing), but reduced to a certain value(admixture excess added) and then decreased, the results show that the surface slurry thickness of aggregate or slurry viscosity of cement has a optimal value. Through the study of the relationship between water-cement ratio and28d strength, Combining with JGJ55-2011"The mix proportion design specifications of ordinary concrete" and obtain the regression coefficients of suitable for preparation tailings concrete. αa、 ab were respectively0.811and0.799.According to the design method of mixture ratio proposed by this paper, the concrete with330kg/m3cement and the mixture’s slump up to220mm,and7d and28d compressive strength of36MPa and62MPa respectively was prepared by the fine sand in full tail sand and waste rock aggregates completely replacing natural sand and gravel aggregates、slag powder and fly ash and retarding polycarboxylate superplasticizer, and the performance indicators meeted the design requirements.Compared with the subway segment concrete which use the same raw materials in factory at present, subway segment concrete is formulated according to the design method of mixture ratio proposed by this paper, which has smaller amount of paste volume, higher mechanical properties, better durability, cost-effective higher performance etc.更多还原