International Concrete Abstracts Portal

Title: Proposed indicators of the effectiveness of curing on site.

Author(s): Luis Fernández Luco. 

Publication: IMCYC

Volume: 1

Issue: 2

Appears on pages(s): 17-29

Keywords: Concrete, curing, non destructive methods, electrical resistivity, air permeability, indicators

DOI:

Date: 1/1/2010

Abstract:
A warm weather condition with a high sunlight percentage and low environmental moisture encourage a premature drying of concrete, from the moment in which it remains exposed. An appropriate curing of the concrete is essential to reduce or to avoid a premature drying and to allow the adequate development of hydration of cement or cementitious materials, to achieve the specified properties of the hardened concrete. A bad curing of the concrete may endanger the concrete quality of the cover to reinforcement, reducing its wearing resistance and its durability. However its influence on mechanical properties is less important, although this judgment has been used as an indicator of the efficiency of the curing. This paper presents different proposals to assess the efficiency of the curing. They are based on the characterization of the concrete cover to reinforcement, both in laboratory and in field. Finally, a new method to identify the effective drying of structural concrete is presented, based on the measurement of electrical resistivity. The proposed procedure is a non destructive, fast and not expensive tool that allows the application of corrective actions when a premature drying is detected, capable of restoring the ideal conditions to continue with the hydration reactions, so as to achieve the design properties, when a premature drying has been detected. According to results, it may be established that methods that measure the fluid transport capacity provide better sensitivity to the effects of premature drying than those that measure the compressive strength, although their use for the application of corrective actions is limited. On the contrary, the measurement of the relative resistivity offers the advantage of allowing the implementation of corrective actions and it can be included into usual control procedures.