Preparation of slag polypropylene fiber concrete

Abstract

The invention discloses a method for preparing slag polypropylene fibre concrete. The sand and stones are mixed according to the mass ratio of 1:1.61, and cement, slag, polypropylene fibre, polyocarboxy acid superplasticizer and water are weighed up, wherein the cement content in concrete is between 0.17 to 0.32 percent; the slag content in concrete is between 0.17 to 0.32 percent; the polypropylene fibre is added according to the volume ratio of polypropylene fibre and concrete of between 0.2 to 0.6 percent; the adding quantity of the polyocarboxy acid superplasticizer is between 3.52 to 11.55ml/kg; the water content in concrete is between 0.17 and 0.22 percent; the concrete of the invention can be directly applied to concrete engineering in fields such as water conservancy, traffic and urban construction, etc., particularly the concrete structure engineering having requirements on tensile stress bearing, repeated dynamic load and anti-fatigue. Because a large amount of slag is added, the cement consumption is reduced, and the polyocarboxy acid superplasticizer is introduced in the preparation of the concrete, under the condition of reducing the manufacturing cost of concrete, the durability of concrete is improved, so that the application of the slag polypropylene fibre concrete can generate bigger economic and social benefits and more obvious ecological benefits.

Description

technical field [0001] The invention belongs to civil engineering, and relates to a method for preparing slag polypropylene fiber concrete. The slag polypropylene fiber concrete prepared by the invention can significantly improve the workability of concrete, reduce slump loss, inhibit plastic cracking of concrete, and improve concrete resistance. Flexural strength, tensile strength, and fatigue resistance, suitable for concrete parts that are subjected to long-term tensile stress and fatigue loads in water conservancy, transportation, urban construction and other projects. Background technique [0002] Concrete is a typical brittle material, its tensile strength is very low, usually only about 10% of its compressive strength, and its flexural strength is only about 9% of its compressive strength. For parts such as concrete pavement, bridge deck, and parking lot that are subjected to repeated dynamic loads of vehicles for a long time, and for hydraulic structures such as chan...

AI Technical Summary

Problems solved by technology

[0021] 2. Effect of slag on concrete performance

[0030] (1) During the process of mixing concrete, the fibers are easy to entangle with each other, agglomerate, construction is difficult, and even the entangled fibers need to be manually torn apart and spread evenly

[0031] (2) The compressive strength of concrete added with fiber drops significantly, the highest one even drops by 50%, and the grade of concrete is reduced. Under the design trend of higher and higher requirements for concrete grade, it is difficult to meet the design requirements and engineering applications

[0032] (3) Each kilogram of fiber ranges from 20 yuan to 280 yuan. According to the current situation, adding 0.9 kilograms of fiber per cubic concrete increases the project cost

So far, no research data have been found on the co-existence of highly dispersed polypropylene fibers, ground slag, and polycarboxylate superplasticizers in cement concrete