Making Test Cubes from Fresh Concrete

Making Test Cubes from Fresh Concrete

1. Introduction

Concrete cubes are made on site to check that the strength of the concrete is above the minimum strength which has been specified.

Making, curing and testing cubes should be carried out in the correct manner. Even small deviations from the standard procedures will usually lead to compressive strength results which are lower than the true strength of the concrete. For example, for each 1% air entrapped there will be a 4 to 5% loss of strength. The procedures for concrete cube making are given in Testing Concrete.

Equipment

a.   Sample tray;

b.   Mould for making test cube;

c.    Spanners;

d.   Scoop;

e.   Steel float or trowel;

f.    Compacting bar;

g.   Vibrating hammer or vibrating table;

h.   Cleaning rags;

i.     A bucket or barrow for transporting the samples;

j.     Polythene sheeting;

k.    Curing tank.