STRENGTH ENHANCEMENT OF REINFORCED PEAT WITH RUBBER WASTE AND MELAMINE UREA FORMALDEHYDE (MUF) RESIN

Peat is classified as a problematic soil due to its low shear strength, low bearing capacity and high compressibility characteristics, which has become a crucial problem in the construction development. The presence of this peaty soil caused difficulties due to its instability and high settlement rate. This paper presents the stabilization of local peat from Kota Samarahan, Sarawak, Malaysia by using two types of processed tire-waste disposal, namely shredded rubber powder (RP) and rubber crumb (RC) at a controlled percentage of 10% of the weight of peat. In this study, liquid Melamine Urea Formaldehyde (MUF) resin was used in different percentages (i.e., 10%, 20%, and 40%) and mixed along with 5% cement to act as a binder. All of the additives were added into the peat at its optimum moisture content. The samples were cured for 7 and 28 days at room temperature and the Unconfined Compressive Strength (UCS) test and California Bearing Ratio (CBR) test are performed on the reinforced peat stabilized with MUF. Based on the findings, the results show that shredded rubber crumb, rubber powder and MUF polymer resin gradually improved the strength of the reinforced peat samples by increasing the effective contact area between the peat and the additive. The highest UCS strength recorded is 438 kPa with a composition of 10% rubber powder, 40% of MUF polymer resin and 5% cement. According to the CBR test findings, the peat increased strength as a result of the addition of 10% rubber crumb, 40% MUF and 5% cement which is 20.3%for soaked condition. Furthermore, the results show that peat soil may be used as a subgrade. The findings of this study indicate that the use of shredded rubber crumb and rubber powder with addition of MUF can improve the engineering properties of peat soil. Thus, these findings may be applied in the construction of subgrade layer

STRENGTH AND DURABILITY EFFECT ON STABILIZED SUBGRADE SOIL

This paper presents the development of strength and durability effect of stabilized soil. The clayey soil collected from Kota Samarahan, Sarawak was admixed with cement, fly ash and rubberchip as an additive for stabilization purposes. The optimum mixture determined was then used as a recommendation for the design guidelines of subgrade based on JKR Standard Specification for Road Works. The stabilized clay specimens were prepared with 5% cement and various fly ash and rubber chips contents, of 5%, 10% and 15%, respectively. The specimens were then cured for 7 and 28 days before subjected to Unconfined Compressive Strength (UCS) tests and California Bearing Ratio (CBR) tests. As observed, the stabilization improved the strength and stiffness of the soil properties significantly. However, the addition of 15% rubberchip shows a reduction in strength for both 7 and 28 days curing period. From the study, the optimum mixture, which fulfilled the JKR Standard Specification was the mixture of 5% cement and 15% fly ash. However, the mixture of 5% cement and 10% rubberchip is also recommended to be used as an alternative to stabilize the subgrade for low volume road

Durability effect on stabilized subgrade soil

Soft clay soil can be categorized as a problematic soil as it has the low strength and high compressibility characteristics. In any highway construction on a soft clay soil, sub-grade soil stabilization is one of the important processes. Therefore, a careful design analysis should be taken for the purposes of any structure built on it. In Sarawak, problematic soils, namely peat, silt and soft clay are the major concern which is inadequate for sub-grade used in the construction of a pavement structure. The focus of this study was mainly the strength and durability of the silty clayey soil. The samples were collected from Kota Samarahan, Sarawak and admixed with cement, fly ash and rubberchip as an additive. The optimum mixture determine from the laboratory is then used as a recommendation for design guideline of sub-grade based on JKR Standard Specification for Road Works and the calculation are performed by using MathCad software. In this study, the stabilized clay specimens were prepared with 5% cement and various fly ash and rubber chips contents, of 5%, 10% and 15%, respectively. The specimens were cured for 7 and 28 days before subjected to Unconfined Compressive Strength (UCS) tests and California Bearing Ratio (CBR) tests. As observed, the stabilization improved the strength and stiffness of the soil properties significantly. However, the addition of 15% rubberchip shows a reduction in strength for both 7 and 28 days curing period. The optimum mixture which fulfilled the JKR Standard Specification was the mixture of 5% cement and 15% fly ash where the value of CBR is 82.6% while the UCS value is 941.69 kPa. However, the mixture of 5% cement and 10% rubberchip can also be used as an alternative to stabilize the sub-grade for low volume road as the CBR value is higher than 30% CBR required by JKR which is 64.66% while the UCS value was 771.77 kPa, respectively

Strength and Durability Effect on Stabilized Subgrade Soil

This paper presents the development of strength and durability effect of stabilized soil. The clayey soil collected from Kota Samarahan, Sarawak was admixed with cement, fly ash and rubberchip as an additive for stabilization purposes. The optimum mixture determined was then used as a recommendation for the design guidelines of sub-grade based on JKR Standard Specification for Road Works. The stabilized clay specimens were prepared with 5% cement and various fly ash and rubber chips contents, of 5%, 10% and 15%, respectively. The specimens were then cured for 7 and 28 days before subjected to Unconfined Compressive Strength (UCS) tests and California Bearing Ratio (CBR) tests. As observed, the stabilization improved the strength and stiffness of the soil properties significantly. However, the addition of 15% rubberchip shows a reduction in strength for both 7 and 28 days curing period. From the study, the optimum mixture, which fulfilled the JKR Standard Specification was the mixture of 5% cement and 15% fly ash. However, the mixture of 5% cement and 10% rubberchip is also recommended to be used as an alternative to stabilize the subgrade for low volume road