Abstract
The hypothesis of two-stage concrete is different from conventional concrete because the particle-to-particle contact of coarse aggregate shrinkage is lower than normal concrete. The important aspect of two-stage (pre-placed aggregate) still remains unclear in its strength. Either by experiment or by theory the strength of two-stage (pre-placed aggregate) concrete has been described in different ways. Since no reliable data is available showing the strength of two-stage (pre-placed aggregate) concrete. It is necessary to investigate its strength at different mixes. This paper deals with the effect of different admixture on the mechanical behavior of two-stage (pre-placed aggregate) concrete. This paper presents also the experimental results of pre-placed, crushed aggregate concreted with thirty-sex different grout mixture proportions. A total of 360 concrete cylinders were tested in unconfined compression and splitting tension at 28 days. On the basis of these results a relationship between the tensile strength and the compressive strength of two-stage (pre-placed aggregate) concrete is statistically derived.