Method for determining finely-grinded mineral slag original content in hardened concrete

Abstract

A method for determining finely-grinded mineral slag original content in hardened concrete belongs to the technical field of building material tests. Fine mineral slag is applied to cement concrete in a large amount, but if the usage amount of the fine mineral slag is too large, concrete easily has the quality problems such as bad workability, reduced strength, easy shrinkage crack, insufficient durability and the like. The invention aims at providing a simple and practicable test method capable of conveniently accurately determining the content of finely-grinded mineral slag in hardened concrete original components. The method possesses two innovation points: firstly, a hydrochloric acid (0.5 M HCl) dissolution process is employed for ensuring that sand content in a concrete sample of the coarse aggregate is removed, and thus the content of the fine aggregate in the hardened concrete original components is effectively determined; and the method is high in measure accuracy and strong in operationality. Secondly, based on mass conservation of CaO content in cement and finely-grinded mineral slag, a mathematic calculation method is provided for determining the doping amount of original finely-grinded mineral slag in the concrete, and the derivation process is precise and the calculation result is accurate.

Description

1. Technical field [0001] The invention belongs to the technical field of building material testing. Specifically, it is a method for determining the content of ground slag in the original components of hardened concrete. The method is scientific in principle, simple and convenient to test, and can accurately determine the content of ground slag in the original components of hardened concrete. 2. Background technology [0002] The ground slag obtained by grinding industrial waste—granulated blast furnace slag has been widely used in cement and concrete, which can reduce the cost of cement concrete and the heat of hydration, and improve the impermeability and long-term durability of cement concrete. Expand the variety of cement concrete, reduce environmental pollution, etc., in line with the development direction of high-performance and green modern materials. my country's annual output of slag powder has exceeded 100 million tons, most of which are used by cement concrete m...

AI Technical Summary

Problems solved by technology

[0003] However, excessive mixing of finely ground slag will lead to problems such as insufficient early strength of concrete and accelerated carbonization (causing easy corrosion of steel bars).

However, since the addition of finely ground slag can save cement costs, to a certain extent, the amount of finely ground slag in cement concrete is often too much, which is likely to cause engineering accidents

In addition, more importantly, once the concrete hardens, it is difficult to detect the amount of finely ground mineral powder in the original concrete.

For this reason, the present invention proposes a method for measuring the original content of ground slag in hardened concrete, which is of great significance for solving the current concrete engineering quality problems caused by the excessive mixing of ground slag

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