Strength Evaluations for Treated peat with Cement and Polypropylene Fibres using CBR Tests
Peat or organic soils are those types of soils that contain a significant amount of organic material derived from plants or animals. Although peat deposits create obvious topographic features such as swamp and bogs, others are buried underground, having been covered with inorganic alluvial soils. These often are difficult to detect and are the source of differential settlements when subjected to loads from civil engineering projects. This article describes a laboratory study on treating peat using ordinary Portland cement (OPC) as binding agent and polypropylene fibers as additive. Due to high initial water content of peat, the usual moist curing technique used to cure the treated peat samples is not used and air curing method is used instead. Beside routine laboratory tests on plain peat, strength evaluation test on the treated peat samples with cement and fibres used in the research was California bearing ratio (CBR). Air curing period used was 90 days for the CBR (soaked and un-soaked) test samples. Various amounts of cements ( 15, 30 and 50%) as well as 0.15% of fibres were used to treat plain peat samples. The result of CBR tests show significant strength improvement of stabilized peat through curing period. Also as the cement amounts increase, treated samples gain more strength, while polypropylene fibers when added to the treated peat with cement not only give more strength values, rather contribute a considerable amount of uniformity and intactness to the cement treated peat
EXPERIMENTAL STUDIES ON LATERITE SOIL STABILIZED WITH CEMENT AND AGGREGATE
The subgrade must be able to support loads transmitted from pavement structure without excessive deformation under adverse climatic and traffic conditions to increase the life of the pavement. It is a well known fact that, all soils do not possess all the desirable qualities for using it as good quality pavement material. When such soils cannot be replaced, its subgrade performance should be increased by several modification techniques. The place where ground water table is high, the strength of subgrade is adversely affected by moisture infiltration to subgrade and base due to capillary action. The purpose of this paper is to evaluate the use of low contents of cement and aggregate in the modification of a lateritic soil properties concerning the behavior of mixtures to use in the base construction. In the present study an effort is made to obtain the optimum dosage of cement for stabilization of locally available lateritic soil. The study incorporates investigations on basic properties of soil. Then the investigations are carried out to study the effect of addition of 10 mm down aggregates to the soil properties added in addition to the obtained optimum cement content to evaluate the extent of modification on MDD, OMC and CBR of the soil. The experimental investigations shown that there is a tremendous increase in the CBR value of the soil treated with cement-aggregate modification. After conducting all the tests see whether it’s strength is suitable for base coarse. In addition, the field cost analysis is also made to compare the cost of construction for various modifications used.
Effects of Nano-SiO2 on tiles manufactured with clay and incinerated sewage sludge ash
In an effort to extend the reutilization of sewage sludge ash and improve the properties of sludge ash tiles, nano-SiO 2 was applied as an additive to sludge ash tiles. Improvements in the tiles were evaluated by factors such as the amount of clay that was replaced by incinerated sewage sludge ash, the quantity of nano-SiO 2 added, and the kiln temperatures. Furthermore, the effects of nano-SiO 2 on the structure and mechanism of sludge ash tiles were studied from both microscopic and macroscopic views. Results indicate that the bending strength of sludge ash tiles increased with increased amounts of nano-SiO 2 . However, due to brittle structures formed on the surfaces of tile bodies at temperature of 1,150°C or higher, reductions in bending strength were correlated with increasing amounts of nano-SiO 2 added.