Stability properties of asphalt mixture incorporating coconut shell

This study aims to evaluate the effect of coconut shell at varying percentages as an aggregatereplacement on the stability properties of the asphalt mixture. The performance of thespecimen was evaluated through stability, stiffness, density and flow tests. Five coconut shellpercentages namely 0%, 10%, 20%, 30% and 40% by weight volumes were used as aggregates replacements in asphaltic concrete. The mixture design incorporating the penetration grade 60/70 bitumen was used for specimen testing. The optimum content of bitumen for asphalt mixtures was 5%. Test results showed that ththe stability, stiffness, density and flow of specimen increased with the increase of coconut shell content to a peak level (10%) and then decreased with further additions of coconut shell. Results also indicated that 10% coconut shell was the optimum replacement as an aggregate in the asphaltic concrete.Keywords: stability; coconut; stiffness; density; flow

Potentials of steel slag and copper mine tailings as construction materials: a review

The present rate of utilisation of mine waste in a country like Malaysia is rather below expectation compared with some advanced countries. Many studies concentrate on a better way to increase the usage of industrial byproducts in order to ease disposal problems. Enormous quantities of steel slag and copper mine tailings are deposited in yards, polluting the environment. Researchers need to pay attention to the effective use of industrial byproducts in construction to address economic and environmental concerns. The potential uses of copper mine tailings and steel slag need to be explored and the negative impact of mine tailings should be reduced by exploring potential uses of these waste materials in the construction industry. Although copper tailings have negative effects on the environment owing to their acidic content, they also have some great economic value in terms of valuable metal contents. The engineering properties of steel slag and copper mine tailings were reviewed and their various areas of application are highlighted

Creep and resilient modulus properties of asphaltic concrete containing black rice husk ash

Black rice husk ash (BRHA) is one of the agro-waste that could be used to improve the properties of asphalt mixture. In this investigation, the BRHA was grounded using a laboratory ball mill with porcelain balls to fine particles size less than 76 μm. Four different BRHA contents were considered in this study namely 0%, 2%, 4% and 6% by weight of binder. The performance of asphaltic concrete containing BRHA was evaluated through resilient modulus and dynamic creep test. It was found that the BRHA can be satisfactorily used as a filler material in order to increase the properties of creep and stiffness modulus asphaltic concrete. Test results also indicate that asphaltic concrete containing 2% to 4% BRHA showed excellent performance to resilient modulus and dynamic creep properties

Marshall stability properties of asphaltic concrete with kaolin clay under aging

The influence of kaolin clay on marshal stability properties of asphaltic concrete AC14 at different aging conditions was presented in this study. These aging conditions were named as un-aged, short-term, and long-term aging. The conventional asphalt binder of penetration grade 60/70 was used in this investigation. Four different levels of kaolin clay replacement were employed (i.e. 0%, 3%, 6%, and 9% by binder weight). Asphalt concrete mixes were prepared at selected optimum asphalt content (5%). The performance was evaluated based on Marshall Stability and voids characteristics. Results indicated the improving stability performance that the mixes modified with kaolin clay have under aging conditions. The result also showed that the use of 6% to 9% kaolin clay can produce more durable asphalt concrete mixtures with better serviceability

Properties of cup lump rubber modified asphalt binder

Recently, the use of natural rubber polymer, such as cup lump rubber in asphalt, has increased due to the fluctuation in natural rubber prices and the demand for modified asphalt. However, information on this new type of rubberised asphalt product is still limited. Thus, a detailed investigation of its performance is necessary for in-depth understanding of this novel material. This study evaluated the effect of cup lump rubber (5%, 10%, and 15% by weight of binder) on the physical, chemical, and rheological properties of asphalt binder. The cup lump rubber was pre-treated with a chemical solvent to soften the rubber structure prior to blending it with asphalt. Results showed that the cup lump rubber is a porous material with high carbon element. Furthermore, the addition of cup lump rubber hardens the asphalt binder and increases resistance against rutting and fatigue cracking