Research On Mix Design Method Of Interlocking-Dense Cement Concrete

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.