The Key Problems' Research For The Preparation Of Lightweight Concrete Made Of Slate Ceramic

Slate ceramic has the advantage of a porous, lightweight, high strength and inhibition of alkali-aggregate reaction in the concrete, so as to slate ceramic lightweight aggregate concrete due to a good earthquake resistance, durability, crack resistance and other properties is used widely in high-rise construction, long-span bridges, urban overpass, subway tunnels and other projects. Lightweight aggregate concrete research is carried out as having great significance for the comprehensive application of building energy efficiency and new green building materials. Content of this paper is based on the the preliminary research work of a company in Yiyang,Hunan applying slate ceramic in concrete, the research focused on the following three aspects:This paper studies the key issues for gravel type Shale in concrete applications,mainly in the following:(1) Reasonable mix design to meet the requirements of gravel type Shale Concrete: Concrete density rating of 1300-1800 kg / m3, compressive strength of not less than 15 MPa, the slump more than 120 mm. Each set of experiments, 0min, 20 min,40min slump and extended in order to reduce the degree. 43% when sand, 7d and 28 d strength of concrete have reached the maximum, respectively 26.8MPa and 28.0MPa.From bleeding, floating aggregate situation and compressive strength, the bulk density of 1800 for gravel type Shale homogeneous concrete improvements, HPMC better than CMC effect. HPMC optimum dosage is 0.8%, then the gravel-type shale concrete compressive strength of 26.6MPa, slump and expand degree respectively264 mm and 595 mm, while concrete 0min, 20 min and 40 min slump over time reduce the slowest and expanded degree, it helps to improve the homogeneity. Experimental data type shale gravel concrete prepared by the statistics in the past, to give a linear fitting curve type dry apparent density of crushed stone and concrete compressive strength Shale between give fitting formula y=0.078+2.904×10-5X1X3-1.799×10-4X2X3.(2) The use of chemical and Accelerated Mortar Bar determination Alkali shale shale concrete and gravel type of concrete aggregate reaction. Join gravel-type shale shale can be suppressed Alkali-aggregate reaction of concrete, gravel type with increasing shale content, the specimen 14 d expansion rate decreases. When the gravel-type shale content reached 0.06%, 14 d expansion shale concrete 0.088,swelling inhibition rate 51.38%. Uniform design in shale concrete gravel type slateceramic composite added, Li OH and fly ash can significantly inhibit alkali aggregate reaction, the experimental group 2 type ceramic gravel mixed with 3%, Li OH4.78 g,Fly 110.00 g, shale concrete alkali aggregate reaction has good inhibitory effect, 14 d expansion rate of only 0.068%. Uniform design regression analysis y=0.078+2.904×10-5X1X3-1.799×10-4X2X3.(3) Comparison of four methods for bulk density rating 1300 kg / m3,1500 kg /m3 of concrete and gravel type Shale 1700 kg / m3 in the post-curing the test results,the growth effects of different ages concrete compressive strength better conservation mode. After releasing the Nature Conservancy and the Conservation flooding alternating manner, for larger bulk density level of gravel-type shale concrete 3d, 7d and 28 d compressive strength of growth are quite good.