Abstract
•The main objective of this study is to investigate the geotechnical properties of soft clay with geofoam beads and bypass cement dust. Also, investigate the possibility of preparing low strength excavatable fill mixtures.•Experimental work was carried out on two groups of mixture (A&B). Different ratios of (Geofoam beads + CBPD) were added to the mixture to study its effect on flow consistency, dry unit weight, unconfined compressive strength, and shear strength.•The experimental work was divided into two groups, each with the same size of 600 cm3. Group A was divided into five sub-samples without the use of geofoam and mixed with increasing percentages of CBPD (50 g) for each sample and different percentages of water. In addition, the B group was divided into five sub-samples and mixed with increasing percentages of geofoam (5 g) for each sample as well as different percentages of water with stable weight of CBPD.•The results of test conducted on the materials illustrated that, cement bypass dust and excess foundry sand can be successfully used to procedure self-compaction, self-leveling excavatable flowable fill material.•The unconfined compressive strength of the studied mixtures with Geofoam ranged between 230 kPa and 120 kPa at Geofoam between 0.32% and 1.35%.•The friction angle and cohesion values of group with Geofoam with ranged between 10o and 22o at CBPD between 0.32% and 1.35%.
Soft clays are usually classified according to their undrained shear strength, Su. Values of Su less than 12.5 kPa are associated with very soft clays. In addition to their low shear strength, soft clays exhibit high compressibility upon loading. Therefore, soft clays are considered to be problematic for foundation purposes. Geo-foam is an industrial material that is characterized by a very low unit weight (20 kg/m3 on average) compared to that of the soil. The density of expanded polystyrene (EPS) ranges from 1.0% to 2.5%, which results in a compressive strength ranging between 70 kPa and 140 kPa and an elastic modulus ranging between 5 MPa and 12 MPa. EPS geo-foam blocks are used in a wide range of geotechnical applications as a lightweight fill material.
The main objective of this study was to investigate the geotechnical properties of soft clays containing geo-foam beads and cement bypass dust (CBPD). We also investigated the viability of preparing low-strength excavatable fill mixtures. To study the effect of (geo-foam beads + CBPD)/soft clay on the fluid-state and hardened properties of new fill, we conducted experiments on two groups of mixtures (A&B). Each mixture contained different ratios of geo-foam beads and CBPD so that we could study the effect of the additive on the flow consistency, dry unit weight, unconfined compressive strength, and shear strength of the mixture. The test results showed that the unconfined compressive strength of the studied mixtures without geo-foam ranged from 271.8 kPa to 1405.14 kPa at CBPD concentrations between 3.88% and 18.63%. The cohesion values for the group containing geo-foam ranged from 50 kPa to 20 kPa at geo-foam percentages between 0.32% and 1.35%. The friction angle of the group containing geo-foam ranged from 10 kPa to 22 kPa at CBPD percentages between 0.32% and 1.35%. Cement bypass dust can be successfully used to process self-compacting, self-leveling, excavatable and flowable fill material.