Properties improvement of cast stone produced using recycled glass waste and lightweight aggregates

Abstract EN

Cast stone (CS) is a form of pre-cast concrete widely, used in architectural applications for decorating and building face in place of natural stone due its superior features.

The present study was an attempt in using of local lightweight aggregate materials (LWAM) as an alternative to percentage of coarse aggregate, and glass wastes as alternatives to percentages of fine aggregate in cast stone normal mixtures with white cement and plasticizer admixture.

The CS products were cured after 24 hrs using of two different processes: water curing (at 23 C° for 3 days) and steam curing (at 60 C° for 14 hrs).

Then the products were characterized by tests of compressive strength, design, absorption, flexure strength and liner drying shrinkage.

The addition of alternative materials was done by trial mixes (M0-M3) through 3 groups (A, B, and C) according to standards.

Group A: design of reference mixtures of CS with compressive strength of 46.3 MPa and the absorption of 6.19%, Group B: design of mixtures containing 50% LWA were 16% lighter than those of Group A with compressive strength of 43.6 MPa and 11% improvement in the absorption, Group C: design of mixtures containing (50 and 75%) glass waste with compressive strength of (47.5-44.3 MPa) and the absorption of (5.3-4.7%), respectively.

The modified steam curing process (curing after 24 hrs casting) done in this study could prove its effectiveness in the achievement of the required compressive strength in comparison with the normal process (direct curing after casting) due to the effect of such new process in providing the more uniform distribution of the cement gel with good physical properties.

Results from the flexural strength test could prove the achievement of the required levels (6.9 – 6.3 at 50 – 75% glass waste addition) recorded in the standard.