Riza Atiq O.K. Rahmat

Expert System to Control Construction Problems in Flexible Pavements

This article discusses how highway engineers face complicated problems that are influenced by various conditions during the construction of flexible highway pavements. Identifying these problems and recommending effective solutions demand considerable engineering expertise, which is difficult to obtain at all construction sites. The development of an expert system can effectively help engineers control and analyze such problems. In addition, an expert system can effectively archive the storage and distribution of expertise among pavement engineers. This article describes the development and evaluation of such an expert system. The first stage in the development of the proposed system was the elicitation of knowledge from written sources and from experts through literature reviews and interviews, respectively. The acquired knowledge was analyzed and classified and then represented in a form containing rules and the rules were subsequently coded as software. This article describes the development and evaluation of the Expert System for the Control of Construction Problems in Flexible Highway Pavements.

Development of disaggregate mode choice models of intercity travel in Libya

Estimation of disaggregate mode choice models to estimate the ridership share on a proposed new (or improved) intercity travel service and to identify the modes from which existing intercity travelers will be diverted to the new or upgraded service constitutes a critical part of evaluating alternative travel service proposals to alleviate intercity travel congestion. In Libya, people heavily relies on private cars for intercity trips increased traffic congestion and road accidents on intercity highways having been the negative impacts. The time is ripe for a policy to simultaneously improve intercity public transport and control car ownership. The aim of this study is to evaluate and analyze the influence on intercity mode choice by proposing a new intercity high-speed train system with high quality of services and new low-cost airline service, in order to reduce car use for intercity travel in Libya, and to enhance intercity road safety. Also, to develop a framework to model travel choice behavior in order to estimate intercity travel demand at nation-level in Libya. The collection of data is conducted through revealed and stated preference surveys handed out to intercity travelers between all major cities in Libya. Comprehensive questionnaires (Arabic and English) will be designed and distributed at airport terminals, bus terminals, and at gasoline stations located midway between the cities under study. The results are hoped to assist decision-makers on all levels to wisely allocate resources to public transportation improvement, and to reduce road accidents on intercity highway and enhance road safety.

A diagnostic expert system to overcome construction problems in rigid highway pavement

AbstractConstructing highway pavements faces complex problems, which are affected by multiple factors, where solution is nearly impossible without expert assistance. Diagnosing such construction problems and suggesting most suitable cost efficient solutions requires significant engineering expertise, which might not be available in all construction sites due to inadequate resource and remote locations. Developing an expert system in this domain is a very effective way to help novice engineers to overcome these problems and to learn about them. Moreover, the system can be used as an archive to document engineering knowledge and to share expertise among the experts in this domain. This article describes the development and evaluation stages of such a system, including knowledge acquisition, knowledge representation, system building, and system verification and validation. The initial knowledge is acquired from literature reviews. More expert knowledge is elicited through interviews and questionnaires. This ...

Influencing modal shift to public transport for sustainable urban development in Tripoli (Libya)

Motor vehicles consume a big share of the worlds oil supply. They are, also, the major source of pollution to the surroundings. Efficient designs, alternative fuels and rational transportation systems can help solve the problem. In Libya, the rapid increase in the use of the private vehicles has resulted in increased traffic congestion, accidents, inadequate parking space and air pollution, among other problems. Earlier studies in this subject, however, focused primarily on car safety issues rather than identifying factors influencing car use and car user mode choice behavior. To provide a solution to these problems, this study focused on providing personal transport users road transport alternatives as a countermeasure aimed at shifting car users to other modes in order to reduce travel time, air and noise pollution and to enhance road safety.

Engineering characterisation of epoxidized natural rubber-modified hot-mix asphalt

Road distress results in high maintenance costs. However, increased understandings of asphalt behaviour and properties coupled with technological developments have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, polymers have become extremely popular as modifiers to improve the performance of the asphalt mix. This study investigates the performance characteristics of epoxidized natural rubber (ENR)-modified hot-mix asphalt. Tests were conducted using ENR–asphalt mixes prepared using the wet process. Mechanical testing on the ENR–asphalt mixes showed that the resilient modulus of the mixes was greatly affected by testing temperature and frequency. On the other hand, although rutting performance decreased at high temperatures because of the increased elasticity of the ENR–asphalt mixes, fatigue performance improved at intermediate temperatures as compared to the base mix. However, durability tests indicated that the ENR–asphalt mixes were slightly susceptible to the presence of moisture. In conclusion, the performance of asphalt pavement can be enhanced by incorporating ENR as a modifier to counter major road distress.

Enhancing mortar strengths by ternary geopolymer binder of metakaolin, slag, and palm ash

Purpose The purpose of this paper is to develop an alternative new ternary geopolymer mortar (MKSP) to resolve a traditional mortar problem which exhibits several disadvantages, including poor strengths and surface microcracks and the CO2 air pollution. Design/methodology/approach The MKSP ternary binder was produced using metakaolin (MK), slag (S), and palm oil fuel ash (POFA) activated with an alkaline mixture of sodium silicate (Na2SiO3) and 10 M NaOH in a mass ratio of 2.5. Seven different mix proportions of MK, slag, and POFA were used to fabricate MKSP mortars. The water-to-binder ratio was varied between 0.4 and 0.5. The mortars were heat cured for 2 h at 80°C and then aged in air. Flexural stress and strain, mortars flow and compressive strength were tested. Furthermore, the mortars were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) analyses. Findings The results showed that the sample MKSP6, which contained 40 percent MK, 40 percent slag, and 20 percent POFA, exhibited high compressive strength (52 MPa) without any cracks and flexural strength (6.9 MPa) at 28 days after being cured for 2 h at 80°C; however, the MKSP7 mortar with optimal strength of 55 MPa showed some surface cracks . Further, the results of the XRD, SEM, and FTIR analyses indicated that the MKSP mortars primarily consisted of a crystalline (Si+Al) phase (70 percent) and a smaller amorphous (Si+Ca) phase (30 percent). Research limitations/implications The MKSP ternary geopolymer mix has three limitations as an importance of heat curing for development early strength, POFA content less than 20 percent to gain high normal strength and delaying the sitting time by controlling the slag content or the alkali activator type. Practical implications The use of geopolymer materials binder in a real building is limited and it still under research, Thus, the first model of real applied geopolymer cement in 2008 was the E-Crete model that formed by Zeobond company Australia to take the technology of geopolymer concrete to reality. Zeobond Pty Ltd was founded by Professor Jannie S.J. van (van Deventer et al., 2013), it was used to product precast concrete for the building structure. The second model was PYRAMENT model in 2002 by American cement manufacturer Lone Star Industries which was produced from the development carried out on inorganic alumino-silicate polymers called geopolymer (Palomo et al., 1999). In 2013 the third model was Queensland’s University GCI building with three suspended floors made from structural geopolymer concrete containing slag/fly ash-based geopolymer (Pathak, 2016). In Australia, 2014, the newly completed Brisbane West Wellcamp airport becomes the greenest airport in the world. Cement-free geopolymer concrete was used to save more than 6,600 tons of carbon emissions in the construction of the airport. Therefore, the next century will see cement companies developing alternative binders that are more environmentally friendly from a sustainable development point of view. Originality/value Production of new geopolymer binder of mortar as alternative to traditional cement binder with high early and normal strength from low cost waste materials, less potential of cracking, less energy consumption need and low carbon dioxide emission.

Early age shrinkage cracking of restrained metakaolin-slag-palm oil fuel ash binder geopolymer mortars

The purpose of this study is to investigate the effects of a ternary geopolymer binder (MKSP) on the early-age shrinkage cracking, creep relaxation, and stress development of a restrained mortar containing alkali activated metakaolin (MK), slag(S), and palm oil fuel ash (POFA). Various mortars were prepared containing different proportions of these binder materials. The ASTM restrained shrinkage test was then conducted to determine the age at cracking, and strengths, free shrinkage and creep were also determined. The results indicate that MKSP with 40% MK, 40% slag, and 20% POFA exhibits the lowest shrinkage strain, possesses sufficient compressive strength (52 MPa) with a creep relaxation (4.2 MPa), and delays the age of mortar cracking for 18 days. Therefore, the use of a ternary MKSP is demonstrated to reduce the early age cracking in mortars. This finding has significant benefits for structures that require a high resistance to cracking, such as pavements

Web-Based Expert System for Optimizing of Traffic Road in Developing Countries

In current times, the increase of road users using road traffic include street carriers, vehicles, pedestrians, buses and other forms of transportation, both individually or in combination, utilizing the universal means to travel. Vehicle regulation and laws governing traffic are traffic laws, whereas road rules are natural regulation and standards that might be advanced in time in facilitating the traffic flow to be methodical and well-timed in emerging countries. Experts of the traffic road system [TRSys] suggests a procedure for road traffic experts and offers supervision and ice advertising on selecting effective and suitable policies. The road traffic development in dealing with traffic-associated complications needs various wide-ranging knowledge and information achievable from road traffic sources for example written sources [books, manuals, technical reports and standards] and traffic expert opinions. A computer tool is utilized in developing the expert system is Web-based expert system Microsoft [PHP]. It is a dominant application containing all the essential services to construct a Windows or Web-based applications for instance expert systems quick and proficient tools. TRSys is an online consultant system in traffic safety to implement a road network in developing countries that can help engineers, consultants, contractors, civil engineering students, and decision makers. The usefulness of the expert system [TRSys] to give recommendations which are appropriate to Road Network for Developing Countries. Traffic Road System [TRSys] is an innovative system advanced in this research to aid junior engineers. It also helps decision-makers and students in identifying traffic complications in developing countries and consequently recommend the application of suitable solutions.

Evaluation of permanent deformation and durability of epoxidized natural rubber modified asphalt mix

The road distresses have caused too much in maintenance cost. However, better understandings of the behaviours and properties of asphalt, couples with greater development in technology, have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, modifiers such as polymers are the most popular modifiers used to improve the performance of asphalt mix. This study was conducted to investigate the use of epoxidized natural rubber (ENR) to be mixed with asphalt mix. Tests were conducted to investigate the performance characteristics of ENR-asphalt mixes, where the mixes were prepared according to the wet process. Mechanical testing on the ENR-asphalt mixes have demonstrated that the asphalt mix permanent deformation performance at high temperature was found to be improved compared to the base mixes. However, the durability studies have indicated that ENR-asphalt mixes are slightly susceptible with the presence of moisture. The durability of the ENR-asphalt mixes were found to be enhanced in term of permanent deformation at high and intermediate temperatures compared to the base asphalt mixes. As conclusion, asphalt pavement performance can be enhanced by using ENR as modifier to face the major road distresses.