Guía de buenas prácticas: fabricación y validación de un equipo para la medida de la resistividad eléctrica en el hormigón. Aplicación en el control del curado

Abstract

The correlation between electrical resistivity

and the properties of concrete, make its

determination becoming increasingly in

a parameter of great interest in concrete

characterization.

It is presented in this work a guide of good

practices for make a resistivity meter of 4-points

and low-cost. We will detail all the necessary

steps essentials in the usage of the device.

Validation from the series of trials. Description

of device and auxiliary elements. Evaluation

of greater stability and precision regarding

different voltage measurements in AC and in DC

calibrated to values of 160 ± 2 Ω.m. and 1200 ±

24 Ω.m.

The 4-points device or Wenner, as it is known,

determines the electrical resistivity in cylindrical

tests of 150 x 300 mm concrete. We compare

these results with other tests carry out by the

application of the direct method and also with

tests run by commercial devices.

We propose a methodology employing resistivity

measurement to establish the degree of concrete

curing during the early stages of hardening

in relation to values obtained in concrete

standards. We also provide experimental detail

of concrete at different stages and curing times.

Concretes of the study were manufactured with

basalt aggregates and Portland cement mixed

with natural Pozzolan (CEM II/B-P 32,5N)