DRYING SHRINKAGE AND MODULUS OF ELASTICITY OF SAND TOTAL LIGHTWEIGHT CONCRETES

The drying shrinkage (ɛs) of two total lightweight concretes (LWC) and two sand lightweight concretes (SLWC) of 35 and 50 MPa cube compressive strength and a normal weight concrete (NWC) of 50 MPa were monitored for a period of up to 3 years. In addition, their strength, stiffness (E), and corrosion potential have also been determined and reported. Whilst NWC 50 gave a drying shrinkage of approximately 700 microstrain, LWC 35 gave drying shrinkage of nearly 1000 microstrain. The results suggest that total and sand LWC shrank 20 and 5% more than the corresponding equal strength NWC, respectively. In spite of the differing values of shrinkage strains, compressive strength, modulus of rupture and modulus of elasticity of the concretes tested, the failure tensile strain capacity (extensibility) of all the concretes was somewhat similar. The results also suggest the ACI code equation to predict E value knowing the compressive strength gives a reasonable estimate of E for the lightweight concretes. Results of corrosion potentials indicated no likely corrosion activity within the test period. Also there was similarity between the values of corrosion potentials for lightweight and normal weight concrete.

• INTRODUCTION

• RESULTS AND DISCUSSION

• CONCLUSIONS

• REFERENCES