Study on chloride-penetration resistance of recycled raw materials concrete

2011 ◽  
Author(s):  
Nian Liu ◽  
Gang Liu
Keyword(s):  
Raw Materials ◽  
Penetration Resistance ◽  
Chloride Penetration ◽  
Chloride Penetration Resistance

scholarly journals The Rapid Chloride Migration Test in Assessing the Chloride Penetration Resistance of Normal and Lightweight Concrete

2021 ◽  
Vol 11 (16) ◽  
pp. 7251
Author(s):  
Jorge Pontes ◽  
José Alexandre Bogas ◽  
Sofia Real ◽  
André Silva
Keyword(s):  
Lightweight Concrete ◽  
Chloride Transport ◽  
Penetration Resistance ◽  
Chloride Penetration ◽  
Migration Test ◽  
Simple Method ◽  
Chloride Migration ◽  
Binder Ratio ◽  
Chloride Penetration Resistance ◽  
Water Binder Ratio

Chloride-induced corrosion has been one of the main causes of reinforced concrete deterioration. One of the most used methods in assessing the chloride penetration resistance of concrete is the rapid chloride migration test (RCMT). This is an expeditious and simple method but may not be representative of the chloride transport behaviour of concrete in real environment. Other methods, like immersion (IT) and wetting–drying tests (WDT), allow for a more accurate approach to reality, but are laborious and very time-consuming. This paper aims to analyse the capacity of RCMT in assessing the chloride penetration resistance of common concrete produced with different types of aggregate (normal and lightweight) and paste composition (variable type of binder and water/binder ratio). To this end, the RCMT results were compared with those obtained from the same concretes under long-term IT and WDT. A reasonable correlation between the RCMT and diffusion tests was found, when slow-reactive supplementary materials or porous lightweight aggregates surrounded by weak pastes were not considered. A poorer correlation was found when concrete was exposed under wetting–drying conditions. Nevertheless, the RCMT was able to sort concretes in different classes of chloride penetration resistance under distinct exposure conditions, regardless of the type of aggregate and water/binder ratio.

Performance of Concrete Made with Recycled Aggregates from Portuguese CDW Recycling Plants

2014 ◽  
Vol 634 ◽  
pp. 193-205 ◽  
Author(s):  
Miguel Bravo ◽  
Jorge de Brito ◽  
Jorge Pontes ◽  
Luís Evangelista
Keyword(s):  
Fresh Concrete ◽  
Penetration Resistance ◽  
Chloride Penetration ◽  
Recycled Aggregates ◽  
Hardened Concrete ◽  
Concrete Compressive Strength ◽  
Performance Loss ◽  
Experimental Campaign ◽  
Significant Performance ◽  
Chloride Penetration Resistance

The objective of this research is the production of concrete with recycled aggregates (RA) from various CDW plants around Portugal. The influence of the RA collection location and consequently of their composition on the characteristics of the concrete produced was analysed. In the mixes produced in this research RA from five plants (Valnor, Vimajas, Ambilei, Europontal and Retria) were used: in three of them coarse and fine RA were analysed and in the remaining ones only coarse RA were used. The experimental campaign comprised two tests in fresh concrete (cone of Abrams slump and density) and eight in hardened concrete (compressive strength in cubes and cylinders, splitting tensile strength, modulus of elasticity, water absorption by immersion and capillarity, carbonation and chloride penetration resistance). It was found that the use of RA causes a quality decrease in concrete. However, there was a wide results scatter according to the plant where the RAs were collected, because of the variation in composition of the RA. It was also found that the use of fine RA causes a more significant performance loss of the concrete properties analysed than the use of coarse RA.

An Experimental Study on the Chloride Penetration Resistance of Recycled Aggregate Concrete

2011 ◽  
Vol 71-78 ◽  
pp. 1255-1258
Author(s):  
Jian Jiang Ding ◽  
Jian Jun Zheng ◽  
Ting Lei ◽  
De Yu Kong
Keyword(s):  
Significant Influence ◽  
Penetration Resistance ◽  
Chloride Penetration ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Aggregate Concrete ◽  
Mixing Method ◽  
Chloride Penetration Resistance ◽  
Theoretical Evidence

The degradation of reinforced concrete structures due to chloride penetration has a significant influence on structural durability. In this study, an experiment is conducted to investigate the effects of the aggregate type, mixing method, and admixture type on the chloride penetration resistance of concrete. Based on the experimental results, it is found that, since more pores and microcracks are included in recycled aggregates, the chloride penetration resistance of recycled aggregate concrete is larger than that of natural aggregate concrete. Slag is more efficient than fly ash in increasing the chloride penetration resistance of recycled aggregate concrete. It is also found that the mixing method has a significant influence on the chloride penetration resistance of recycled aggregate concrete. These conclusions can provide theoretical evidence for the design optimization of recycled aggregate concrete properties.

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