Prediction of Chloride Ion Penetration of Recycled Aggregate Concrete

Abstract

This paper provides a literature review and analysis of the various influencing aspects related to the use of recycled aggregates, sourced from construction and demolition waste, on the chloride ion penetration of concrete. A statistical analysis on the effect of incorporating increasing amounts of recycled aggregates of different type, size, and class on the chloride ion migration and total charge passed of concrete is also presented. The paper also presents the relationship between these properties and the corresponding compressive strength. The results show strong correlations between these parameters, which are independent of other aspects related to recycled aggregate use and made it possible obtaining a relationship between the values acquired via NT Build 492 and ASTM C1202.

Influence of fly ash and decreasing water-powder ratio on performance of recycled aggregate concrete

“…Generally, the use of mineral additions was found to have a positive effect on the resistance to chloride ion penetration. This improvement occurred at a fairly similar rate in RAC with higher replacement levels, and in the corresponding NAC [1]. The advantages of using fly ash in recycled aggregate concrete have been more intensively investigated over the last two decades.…”

“…According to estimation of concrete resistance to chloride ion penetration given in [12], the concretes with RCA (R13 and R23) could have a good resistance (2-8x10- The presented results refer to concrete samples at the age of 28 days. Therefore, it is expected that other samples, to be examined at a later time, will show greater resistance to chloride penetration [1]. …”

“…Therefore, the construction and demolition waste recycling is a vital step towards environmental sustainability in construction industry [1]. Recycled coarse aggregate, and especially the recycled concrete aggregate (RCA), has been used for more than seventy years in civil engineering.…”

“…The general conclusion is that the strength and durability properties of concrete containing RCA are worse than the comparable properties of concrete containing natural aggregate. There is a consensus in literature that durability properties decrease with an increase in the RCA replacement level, [1]. However, these properties are still sufficient for some applications in the civil engineering practice.…”

Recycled concrete with coarse recycled aggregate. An overview and analysis

“…The diffusion mechanism of chloride ions occurs in a way comparable to that of carbonation and is mostly dependent on the porosity of the cementitious matrix. For this reason, the literature's findings have revealed that the increasing incorporation of coarse RCA tends to lead to higher chloride ion penetration depths (21,99,104,(120)(121)(122)(123)(124)(125).…”