TEXTURE DEPTH DETERMINATION FOR STONE MASTIC ASPHALT (SMA).

The primary road surface characteristics that affect users are safety, noise and riding quality

A Prototype Expert System for the Selection of Road Construction Materials

A prototype for an expert system in road construction material selection system, which is based on the outcomes of Friedman and multiple comparisons statistical methods was developed. The outcomes were acquired through questionnaires from selected pavement experts. The factors affecting pavement materials under each particular site condition were incorporated into the specific rules of the system. The system knowledge-base was extracted from the statistical testing outcomes and then rearranged and compiled prior to the development of the system. Visual Basic 6.0 was adopted as the programming tool for development of the system, while the knowledge-base of the separate system was kept in Microsoft Access 2000. The prototype expert system can be used to emulate part of the professional reasoning capabilities based on the knowledge of a pavement expert or a specialist to solve problems on materials selection. The system can help road designers to improve their professional ability to evaluate all available materials even before carrying out any laboratory tests

Paraoxonase 1 activity as a predictor of cardiovascular disease in type 2 diabetes

The role of paraoxonase 1 in cardiovascular disease complications in type 2 diabetes mellitus is not fully understood. We studied paraoxonase activity towards paraoxon in 188 non-diabetic and 140 diabetic subjects using general linear models and univariate analysis. Adjusting for age revealed a reduction in activity towards paraoxon was associated with a significant increase in risk (p=0.023) for cardiovascular disease complications in diabetic patients. Multivariate analysis of two plasma measures of paraoxonase activity using paraoxon and diazoxon also showed reduced paraoxonase activity towards paraoxon was associated with a significant increase in risk (p=0.045) for cardiovascular disease complications in diabetic patients. These analyses showed that a reduced paraoxonase activity towards paraoxon was associated with ethnicity. Based on multivariate analysis, subjects of Malay ethnic origin have significantly higher than expected activity (p=0.008, compared to Indians), towards paraoxon than subjects of Chinese origin who in turn had higher than expected paraoxonase activity (p=0.028, compared to Indians) Indian subjects

Modification Of Aggregate Grading For Porous Asphalt.

In the 1970’s, the fatality index on Malaysian roads exceeded 20. In 1991, a Cabinet Committee on Road Safety was set up to come up with measures to reduce the predicted number of deaths by 30% or translated into a fatality index of 3.14 by the turn of the century. Among the measures suggested included the application of porous asphalt

Effect of Mineral Filler Type and Particle Size on the Engineering Properties of Stone Mastic Asphalt Pavements

This study examines four types of industrial and by-product waste fillers, namely limestone dust (LSD), which was the reference filler; ceramic waste dust (CWD); coal fly ash (CFA), and steel slag mixture (SSD). The filler consisted of an aggregate (10% of total weight) with three proportions: 100% passing 75μm, 50% passing 75μm/20μm, and 100% passing 20μm. Comprehensive laboratory tests were performed to determine the impact of different types and particle sizes of fillers on the engineering and mechanical properties of fine mastics and stone mastic asphalt mixture. The results indicate that the application of industrial by-products used as fillers improves the engineering properties of stone mastic asphalt mixtures. The increased stiffness due to the addition of the filler is represented by an increase in the softening point, viscosity, stability, and resilient modulus, as well as a decrease in penetration. The optimum asphalt content increased with the decrease in filler particle size for LSD and SSD, and decreased for CWD and CFA. It was also determined that the filler type and particle size has a significant effect on the mixture properties. Among these three proportions, the samples prepared with the filler size proportion of 50/50 gave the best value in terms of stability, Marshall quotient, and resilient modulus than the other filler size proportions

Effect of mineral filler type and particle size on the engineering properties of stone mastic asphalt pavements

This study examines four types of industrial and by-product waste fillers, namely limestone dust (LSD), which was the reference filler; ceramic waste dust (CWD); coal fly ash (CFA), and steel slag mixture (SSD). The filler consisted of an aggregate (10% of total weight) with three proportions: 100% passing 75μm, 50% passing 75μm/20μm, and 100% passing 20μm. Comprehensive laboratory tests were performed to determine the impact of different types and particle sizes of fillers on the engineering and mechanical properties of fine mastics and stone mastic asphalt mixture. The results indicate that the application of industrial by-products used as fillers improves the engineering properties of stone mastic asphalt mixtures. The increased stiffness due to the addition of the filler is represented by an increase in the softening point, viscosity, stability, and resilient modulus, as well as a decrease in penetration. The optimum asphalt content increased with the decrease in filler particle size for LSD and SSD, and decreased for CWD and CFA. It was also determined that the filler type and particle size has a significant effect on the mixture properties. Among these three proportions, the samples prepared with the filler size proportion of 50/50 gave the best value in terms of stability, Marshall quotient, and resilient modulus than the other filler size proportions

Laboratory Evaluation of Malaysian Cellulose Oil Palm Fiber for Use in Stone Mastic Asphalt Mixes

The primary agricultural product of Malaysia is palm oil. As a result, some two million tons of empty fruit bunch wastes are being dumped behind palm oil mills every year. This is causing serious environmental problems. This paper discusses a study undertaken in 1996 to look into the suitability of the Malaysian oil palm fiber in Stone Mastic Asphalt (SMA) mixes. The oil palm fiber was analyzed and compared with other traditional European fiber that is commonly used in gap-graded mixes. Several experiments were carried out on the fiber including the Fiber Drain Down Test (FDDT) and Morphological analysis using Scanning Electron Microscope (SEM). Besides this, chemical analysis was also carried out with a variation of cellulose content and particle size. The results of the laboratory analysis showed that the Malaysian Cellulose Oil Palm Fiber (COPF) has great potential to be used in SMA mixes

Paramedics’ perception on video assisted learning method in learning emergency skills

Information technology use in healthcare education has become a popular medium of instruction. One of the medium of instruction is video assisted learning (VAL). The use of VAL as an instructioemergency skills is not new. However, there are lack of studies on the perception of using this method in learning emergency skills. This qualitative study involved four focused discussion groups following a VAL instruction on emergency skills. A total of 20 paramedics were divided into four groups. They were involved in a focussed discussion after a VAL instruction session. Findings reveal that the paramedics perceived three major themes which were categorized as : i) advantages of video as teaching tool, ii) barrier in using video as a teaching tool; and iii) suggestions on using video as teaching tool. The findings indicate that the paramedics perceived VAL as a potential tool for learning emergency skills. However, they suggested the language of instruction should be in their mother tongue for better understanding. This implies that using English language has disadvantage in technology enhanced learning for better understanding

An overview of moisture damage performance tests on asphalt mixtures

This paper presents a review of moisture damage performance tests on asphalt mixtures. The moisture damage remains to be a detriment to the durability of the Hot Mix Asphalt (HMA) pavement. Moisture damage can be defined in forms of adhesive failure between bitumen and aggregates and cohesive failure within bitumen. Aggregate mineralogy, bitumen characteristics and anti-stripping additive dominantly influence the performance of asphalt mixtures towards moisture damage alongside construction methods, climate and traffic loading. Various laboratory test methods have been developed to quantify the moisture damage performance of asphalt mixtures by resembles the action in the field, including qualitative test such as Boiling Water Test (ASTM D3625) and quantitative tests such as Modified Lottman Test (AASHTO T283). Both of these tests consist of two phases, which are conditioning and evaluation phase. This paper will review the effectiveness of the selected available tests based on various asphalt mixtures materials. Generally, this study indicates that asphalt mixtures consisted of limestone aggregates, modified bitumen and addition of anti-stripping additives will provide more resistant towards moisture damage

Review of subcontracting practice in construction industry.

Great numbers of traders from different specialisation makes construction industry is a complicated and unique industry. To overcome the demand on special expertise, advanced equipment, and huge investment cost, letting out work to subcontractors has been a norm in construction industry. Nevertheless, large presence of subcontracting poses challenges to contractors, client and their project management teams to manage such a large, diverse and fragmented group of subcontractors. Success of a construction project is essentially depending on the ability of general contractor to select the appropriate subcontractor during bidding process, and the sufficient management of subcontractor during construction. This paper served as a summary of literature review done on types of subcontractor, problems generated by subcontractor, and current proposed methods to enhance the subcontracting practice