Experimental study of geotechnical characteristics of crushed glass mixed with Kaolinite soil

The Geotechnical properties of adding crushed curbside-collected glass to Kaolinite S300 with various percentages of 10 to 50% were experimentally evaluated. Crushed glass passing the 2.36 mm (#8) sieve, and retaining on 1.18 mm (#16) selected for this study is collected from a different area in Johor Bahru, Malaysia. Measured hydraulic conductivities were on the order of 2.33E-6 and 1.87E-5 for 10% and 50% respectively. The result shows increment in the maximum dry density from 1.615mg/m3 at 10% to 1.908mg/m3 at 50% of addition of crushed glass with the optimum moisture content of 18.35% and 7.4% respectively. Friction angles from the direct shear test were evaluated between 12 to 25 degrees at normal stresses of 56.4 to 219.9 kPa. The result shows that the unconfined compression strength of Kaolinite S300 mixed with crushed glass is increased from 5.26 kPa at 10% addition of crushed glass up to 17.52 kPa at 50%. It can be concluded that the crushed glass is environmentally clean, readily available, and relatively low-cost material that can be one of the replacements for traditional aggregate to enhance the geotechnical properties of soft cohesive soils

Stabilization of backfill using TDA material under a footing close to retaining wall

Reutilization of solid waste such as Tire Derived Aggregate (TDA) and mixing it with soft soil for backfill material not only reduces the required volume of backfill soil (i.e., sand-mining procedures; reinforcement), but also preserves the environment from pollution by recycling. TDA is a widely-used material that has a good track record for improving sustainable construction. This paper attempted to investigate the performance of Kaolin-TDA mixtures as a backfill material underneath a strip footing and close to a retaining wall. For this purpose, different types of TDA i.e., powdery, shredded, small-size granular (1-4 mm) and large-size granular (5-8 mm), were mixed with Kaolin at 0, 20, 40, and 60% by weight. Static surcharge load with the rate of 10 kPa per min was applied on the strip footing until the failure of footing happened. The behaviour of samples K80-G (1-4 mm) 20 and K80-G (5-8 mm) 20 were identical to that of pure Kaolin, except that the maximum footing stress had grown by roughly three times (300-310 kPa). Therefore, it can be concluded that the total flexibility of the backfill and shear strength of the strip footing have been increased by adding the TDA. The results indicate that, a significant increase in the failure vertical stress of the footing is observed at the optimum mixture content. In addition, the TDA increases the elasticity behaviour of the backfill

Evaluating the compression index of fibrous peat treated with different binders

Fibrous peats feature high compressibility and correspondingly very low strength. In this study, an investigation into the compressibility of untreated and stabilized fibrous peat with different binders—namely cement, lime, gypsum, and fly ash—is presented. The technique adopted for sample preparation was aimed at simulating the in-situ condition of the deep soil mixing technique. For this purpose, the binder dosages were selected in the range of 100–400 kg/m 3 of wet fibrous peat at its natural water content. This binder range was determined based on the unconfined compressive strength of the treated samples. All the treated samples were cured for 14, 28, and 90 days in both air and water. The consolidation behavior of the treated peat samples was assessed by performing a Rowe cell consolidation test. The test results revealed that the increase in cement, fly ash, and gypsum contents led to considerable decreases in compression indices of the treated fibrous peat. No significant changes in the compressibility properties of lime-treated peat were observed. In addition, the inclusion of well-graded sand as filler decreased the compression indices of the treated samples significantly. Finally, in comparison with air curing, the use of the water curing technique for all the stabilized samples, regardless of binder type, showed better performances