This paper presents the engineering properties and compressibility behavior of various types of tropical peat soil collected from several locations in Malaysia. These soils represented fibric, hemic and sapric type of tropical peat with organic content ranging from 70% to 90%. The correlations of the various basic engineering properties of the tropical peat soils have been found to be close and new equations have been established. Loss on ignition (Organic Content) appears to be a very useful parameter for the peat. It correlates well with the natural water content, liquid limit, density and specific gravity. Compressibility behavior of various type of peat soil was measured using Rowe Cell consolidation test for accuracy and conventional oedometer test for comparison purpose. Compressibility index Cc and Cα was identified as two crucial parameters to estimate settlements in peat soil. Parametric study has been carried out at the end of the study to foresee the effect of surcharge on fibric, hemic and sapric peat ground. Based on the results obtained, it shows that fibric peat recorded the highest settlement followed by hemic and sapric peat with increase in consolidation pressure.

This study aims to obtain the relationship between density and compressive strength of foamed concrete. Foamed concrete is a preferred building material due to the low density of its concrete. In foamed concrete, the compressive strength reduces with decreasing density. Generally, a denser foamed concrete produces higher compressive strength and lower volume of voids. In the present study, the tests were carried out in stages in order to investigate the effect of sand–cement ratio, water to cement ratio, foam dosage, and dilution ratio on workability, density, and compressive strength of the control foamed concrete specimen. Next, the test obtained the optimum content of processed spent bleaching earth (PSBE) as partial cement replacement in the foamed concrete. Based on the experimental results, the use of 1:1.5 cement to sand ratio for the mortar mix specified the best performance for density, workability, and 28-day compressive strength. Increasing the sand to cement ratio increased the density and compressive strength of the mortar specimen. In addition, in the production of control foamed concrete, increasing the foam dosage reduced the density and compressive strength of the control specimen. Similarly with the dilution ratio, the compressive strength of the control foamed concrete decreased with an increasing dilution ratio. The employment of PSBE significantly influenced the density and compressive strength of the foamed concrete. An increase in the percentage of PSBE reduced the density of the foamed concrete. The compressive strength of the foamed concrete that incorporated PSBE increased with increasing PSBE content up to 30% PSBE. In conclusion, the compressive strength of foamed concrete depends on its density. It was revealed that the use of 30% PSBE as a replacement for cement meets the desired density of 1600 kg/m3, with stability and consistency in workability, and it increases the compressive strength dramatically from 10 to 23 MPa as compared to the control specimen. Thus, it demonstrated that the positive effect of incorporation of PSBE in foamed concrete is linked to the pozzolanic effect whereby more calcium silicate hydrate (CSH) produces denser foamed concrete, which leads to higher strength, and it is less pore connected. In addition, the regression analysis shows strong correlation between density and compressive strength of the foamed concrete due to the R2 being closer to one. Thus, production of foamed concrete incorporating 30% PSBE might have potential for sustainable building materials.

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This paper presents the compressibility of fibrous peat reinforced with cylindrical cement columns. The effects of the cement column diameter on the compressibility have been investigated in this study. The results indicated that compressibility index C c and C a decreased with increasing diameter of the cement column. Specimens with 45 mm (area ratio = 0.09) diameter and 60 mm (area ratio = 0.16) diameter of cement columns were cured for 7, 14 and 28 days, after which they were subjected to Rowe Cell consolidation test. Results are also presented from tests conducted on groups of cement columns using four (area ratio = 0.04) and nine (area ratio = 0.09) columns of 15 mm diameter each to investigate the influence of the number of cement columns on compressibility of peat. Apart from that various proportions of cement were used to form cement columns in order to study the influence. Based on the results obtained, it shows that cement columns can successfully reduce the compressibility of fibrous peat.

This paper discusses some of the methods and recent technologies in utilizing cheap marginal land such as tropical peat for housing scheme. Buildings on peat are usually suspended on piles, but ground around it may still settle. Therefore a suitable method of construction should be tackle to overcome serious problem such as localized sinking and slip failure, massive primary and long term (creep) settlement. With the ever increase in the cost of living and the decrease in suitable land for construction, avoidance of marginal tropical peat soil is never going to be the popular choice among the developers and town planners. This paper gives some insights on the construction methods that could be possibly employed to develop marginal ground such as tropical peat soil.

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Abstract:The objective of this research project was to find a potential replacement for the conventional pile foundation principally for peat soil. It is fundamentally meant for lightweight and impermanent agricultural farm structures. Preceding the design and development of the foundation the physical characteristics of the in-situ peat such as; peat depth, soil consolidation, soil compressibility, water table, liquid limit, soil moisture content, soil bulk density, loss on ignition, soil bearing capacity and soil shear strength were verified. Two types of foundation designs i.e. single shell and pad foundations were assessed. Both utilized Expanded Polystyrene (EPS) as the footing material. They were conceptually designed as floating foundation employing the weight compensation technique. The soil bearing capacity, soil shear strength, self-load and the lateral wind-load are factors taken into consideration in the footing design. The total design load was considered at 100 kg per foundation. The water table fluctuation, soil surface subsidence, the foundation vertical movement and its stability were constantly monitored. After a scheduled period, the foundations continue to stay intact.

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