Comparison of Material Properties of SCC Concrete with Steel Fibres Related to Ingress of Chlorides

Abstract

The paper focuses on the evaluation of chloride ion diffusion coefficient of self-compacting concrete with steel fibre reinforcement. The reference concrete from Ordinary Portland Cement (OPC) and Self-Compacting Concrete (SCC) with several values of added steel fibres—0%, 1% and 2% of weight—were cast in order to investigate the effect of fibres. The three procedures of diffusion coefficient calculation are presented—rapid chloride penetration test, accelerated penetration tests with chloride as well as the surface measurement of electrical resistivity using Wenner probe. The resulting diffusion coefficients obtained by all methods are compared and evaluated regarding the basic mechanical properties of concrete mixtures.

Durability Characteristics of Concrete Mixture Based on Red Ceramic Waste Aggregate

“…In the case of In order to be able to evaluate the suitability of the SLWAC, the reference concrete mixture shall be selected. Therefore, ordinary concrete mixture (OPC), whose composition is similar to those commonly used for structural concrete, was taken over from the research of the co-authors [22] for the comparison of the mechanical and diffusion properties. Available OPC data can be used because the methodology of measuring resistivity and chloride profile is the same as in the case of SLWAC.…”

“…This theoretical approach is used to obtain the diffusion coefficient. The procedure of measurement and calculation process are described in [17,22,[38][39][40]. The Wenner Array Probe can be used for the measurement of surface resistance.…”

“…Since the suitable tool for grinding a thin layer of the concrete surface and subsequent collection of the powder, which is a process described in NT Build 443, is not available, the process of collecting the concrete powder needed to be slightly modified [22]. A sampling of concrete powder in layers of chloride profile was conducted by drilling.…”

“…The static modulus of elasticity was determined by the tests procured on standard cylinders. The tests and evaluation of results are described in detail in [9,22]. Measured mechanical properties are used for the first and basic comparison of the waste aggregate concrete mixture and the reference mixture.…”

“…The resulting diffusion coefficient of SLWAC determined by NT Build 443 is compared to the results obtained by resistivity measurements [21] and to the results of the reference concrete mixture, which is based on an ordinary concrete made of commonly used natural aggregate and Portland cement (OPC). The reference OPC mixture has been designed and tested for mechanical and durability characteristics in previous research [22] by co-authors and the methodology remained the same for SLWAC. Therefore, the reason for choosing this type of mixture and tests is also the availability of data of reference mixture and ensuring the repetition of the same process in case of SLWAC for a successful comparison.…”