【作者】 田尔布；

【导师】 马骉；

【作者基本信息】 长安大学 ， 道路与铁道工程， 2008， 硕士

【摘要】 水泥混凝土广泛应用于基础建设各个领域,随着经济发展、科技进步,人们对其使用品质要求越来越高。现行混凝土配合比设计方法设计的混凝土以悬浮密实型结构为主,易在集料与水泥石粘结处发生破坏,且尚未充分发挥粗集料的作用。为此,本研究在体积法和干涉理论的基础上,提出了粗集料嵌锁骨架结构与嵌锁密实型水泥混凝土概念,并对其工作性、强度特性及其设计方法开展了系统研究,以期节约成本,提高混凝土性能,具有重要工程实用价值。粗集料嵌锁骨架结构是指骨架颗粒与填充颗粒之间充分嵌锁、紧密排列、不干涉或少干涉,使其达到合理密实状态时形成一个多级空间骨架结构;在此基础上,利用砂填充粗集料振实剩余空隙,再用水泥净浆润滑和填充粗集料与砂的混合料的剩余空隙,形成嵌锁密实型水泥混凝土。粗集料振动填充试验表明,采用粒径具有或接近1/2倍关系的颗粒填充骨架颗粒可以形成嵌锁骨架结构,其临界状态为混合料振实剩余空隙率变化曲线的第一波谷值,最佳集料填充比约为40%。据此提出了粗集料嵌锁骨架结构级配设计方法,并编制了粗集料嵌锁骨架结构设计软件QSGJ-V1.0。工作性试验得出,水灰比、填充比与坍落度基本呈正比递增关系,砂率与坍落度关系则随着水灰比的增大由上凸抛物线逐步过渡为波动递减曲线。强度试验表明,水灰比、填充比、砂率与强度基本呈反比递减关系。在不同砂率下,分别回归水灰比、填充比与坍落度和强度的关系公式,以及7d抗压强度与28d抗压强度、抗压强度与抗弯拉强度的计算公式。综合研究成果,提出了嵌锁密实型混凝土配合比设计方法,并与现行设计方法对比表明,同等强度、工作性要求下,嵌锁密实型水泥混凝土比现行设计方法确定的混凝土的经济性更好,且设计方法可操作性强,简便实用,可以直接应用于工程实际。更多还原

【Abstract】 Concrete widely used in infrastructure construction in various fields, along with economic development, scientific and technological progress, people use their increasingly high-quality. The existing design of concrete mix designed to suspension-compacting concrete structure-oriented and easy to damage in bonding of aggregate and cement, and has yet to give full play to the role of coarse aggregate. For this reason, basing on the Volume and Interference theory, the study put forward a coarse aggregate embedded lock skeleton structure and embedded lock dense concrete concept, and research systematically on its working, strength and design, with a view save costs and improve the properties of concrete, important works have practical value.The coarse aggregate embedded lock skeleton structure is that skeleton particles embed fully, work closely, non-interference or less with peanuts, and to reach a state of reasonable density to form a multi-level space frame structure; on this basis, use sand to fill coarse aggregate remaining gap, use cement paste to lubricate and fill the remaining gap of coarse aggregate and sand mixture, forming dense embedded lock-cement concrete. Coarse aggregate filled vibration tests showed that, using a particle size or close to 1/2 times the particles can be filled with a skeleton embedded particles lock skeleton structure, its critical state for the remaining mixture-air void is the first curve trough value, the best aggregate filling ratio of about 40 percent. Accordingly, put forward the coarse aggregate embedded lock-frame structure design and prepared of the coarse aggregate embedded lock skeleton structure design software QSGJ-V1.0. Test drawn work, the slump increase with water-cement ratio, filling ratio, the relations of Sand rate and the slump is from convex parabolic gradual transition to fluctuations in descending curve with the increase of water-cement ratio. Strength tests show the strength reduces almost with water-cement ratio, filling ratio, sand rate. At different rates, regressive the strength and slump calculating formula with water-cement ratio and filling rate, regressive the 28d compressive strength calculating formula with the 7d compressive strength, regressive the bending strength formula with compressive strength. Comprehensive research results, put forward the embedded lock-dense concrete mix design method, and compared the existing design methods show that the same intensity, working, embedded lock density cement concrete cement concrete mix design are better than the existing concrete on economy better, can be highly workable, simple and practical, can be directly applied to engineering practice.更多还原