Munder Bilema - Academia.edu (original) (raw)

Papers by Munder Bilema

Construction and Building Materials

Sustainability

The crumb rubber (CR) recycled from waste tyres could be a viable alternative in achieving green ... more The crumb rubber (CR) recycled from waste tyres could be a viable alternative in achieving green pavements that offer exciting new markets to global investors. Adding CR into flexible pavements enhances their performance and ensures environmental sustainability. This paper will discuss the production variables, CR sizes and contents, blending techniques, optimum bitumen contents, morphology, standard characteristics, rheological characteristics, mechanical performance, greenhouse gas emissions, energy consumption and life cycle cost. This review study found that compared to traditional asphalt mixtures, the CR-modified asphalts had superior performance and longer service life. However, the dearth of information on several factors in CR asphalt production, including greenhouse gas emissions, energy consumption and life cycle cost during recycling, causes many agencies in the global asphalt industry to continue employing costly, energy-consuming additives such as styrene-butadiene-sty...

Frontiers in Materials

Ultra-high performance concrete (UHPC), an advanced class of fiber-reinforced cementitious materi... more Ultra-high performance concrete (UHPC), an advanced class of fiber-reinforced cementitious material with extraordinary mechanical properties, low permeability, shrinkage and creep, and high energy absorption capacity, has seen steady increase in use, with applications covering construction of new members and retrofit of existing ones. Fibers are added in the UHPC mix to bridge cracks, carry tensile stresses, and contribute greatly to member ductility and load capacity. Hybrid fibers comprising micro and macro types are beneficial where the first type resists microcracking and the second targets macrocracking. This study investigates the effects of blending three fiber types, namely, hooked-end steel (referred to as type 1, representing macro fibers class), straight-end steel (type 2, intermediate size fibers), and carbon (type 2, micro size fiber), on the mechanical properties of UHPC. Experimental tests were performed to characterize the following mechanical properties: flowability...

International Journal of Environmental Research and Public Health

The environmental concerns of global warming and energy consumption are among the most severe iss... more The environmental concerns of global warming and energy consumption are among the most severe issues and challenges facing human beings worldwide. Due to the relatively higher predicted temperatures (150–180 °C), the latest research on pavement energy consumption and carbon dioxide (CO2) emission assessment mentioned contributing to higher environmental burdens such as air pollution and global warming. However, warm-mix asphalt (WMA) was introduced by pavement researchers and the road construction industry instead of hot-mix asphalt (HMA) to reduce these environmental problems. This study aims to provide a comparative overview of WMA and HMA from environmental and economic perspectives in order to highlight the challenges, motivations, and research gaps in using WMA technology compared to HMA. It was discovered that the lower production temperature of WMA could significantly reduce the emissions of gases and fumes and thus reduce global warming. The lower production temperature also...

IOP Conference Series: Earth and Environmental Science, 2022

Cold mix asphalt (CMA) is a versatile and energy efficient mixture often prepared at ambient temp... more Cold mix asphalt (CMA) is a versatile and energy efficient mixture often prepared at ambient temperature. Efforts to improve the performance of CMA mixtures recorded appreciable success. Nonetheless, the critical performance measures of moisture and abrasive resistance still baffles researchers. Additionally, CMA’s design, production, testing, and site application is bedevilled by slow rate of strength gain, high void content, and absence of a globally acceptable mix design. This study aimed at assessing CMA’s durability measures using the modified Lottman (moisture damage) and Cantabro tests by adding a 3% palm oil fuel ash (POFA) as filler replacement and 3% cement. Fast-curing mixtures fabricated with a cationic quick-set (CQS-1h) and a rapid-set (RS-1K) emulsion both of medium viscosities with a nominal maximum aggregate size (NMAS) of 4.75 mm were evaluated. In addition to improving the Marshall volumetric properties, POFA’s inclusion is aimed at improving adhesion thereby enha...

Jurnal Kejuruteraan, May 30, 2022

Rheology can be defined as the primary measurement associated with bitumen flow and deformation c... more Rheology can be defined as the primary measurement associated with bitumen flow and deformation characteristics. In the long term, DSR testing consumes a long time, expensive cost and skilled labour to operate equipment or machines in the laboratory. The complex modulus, G* and phase angle, δ, are essential parameters for characterising and predicting the rheological behaviour of unaged bitumen (UB) and polymer-modified bitumen (PMB) in the model. This study developed three regression models using Azure machine learning (AML) to predict the rheological behaviour of UB and PMB. There are three types of data used as input data to develop the regression model: temperature, frequency, and modified material content. Regression models were developed with three processes or steps that need to be prioritised: data collection, model preparation, and model validation. Algorithms used in model development are decision tree regression (DFR), boosted decision tree regression (BDTR) and linear regression (LR). The results show G* and δ values. The R 2 values in the G* and δ predictions obtained from the DFR models are 0.8199 and 0.9480, respectively. Moreover, the R 2 values in the G* and δ predictions obtained from the LR models are 0.4219 and 0.7836, respectively.

Recycling

The Sultanate of Oman has experienced rapid development over the last thirty years and has constr... more The Sultanate of Oman has experienced rapid development over the last thirty years and has constructed environmentally friendly and sustainable infrastructure while it continues to find economical alternative resources to achieve the goals of the Oman 2040 vision. The primary concerns are preserving natural resources and reducing the impact of carbon dioxide (CO₂) emissions on the environment. This review aims to encourage the sustainable use of reclaimed asphalt pavement (RAP) materials in pavement construction and focuses primarily on employing RAP materials in new pavement projects. Currently, new construction projects utilise a significant percentage of demolished asphalt pavement to save costs and natural resources. The key issue that arises when mixing RAP into new asphalt mixtures is the effects on the mixtures’ resistance to permanent disfigurements, such as fatigue cracks, that influence asphalt mixture performance. Numerous studies have assessed the impact of using RAP in ...

MATEC Web of Conferences, 2017

Pedestrian are among those who were contributed to the increase of road accidents and identified ... more Pedestrian are among those who were contributed to the increase of road accidents and identified as vulnerable rod user in the country. Various aspects and factors that lead to the accident among the pedestrian and other road users are needed to be studied, so that the safety all road user should be improved. This study was conducted to identify the characteristics of user demographic in terms of age, gender, employment and others. In addition, the characteristics and the perception of pedestrians were also evaluated in order to achieve the objectives of this study. The observational study was carried out to the users on the usage of pedestrian facilities. The study was focused in the city area of Batu Pahat. The type of pedestrian facilities included pedestrian walkaways, pedestrian bridges and zebra crossings. A total of 200 sets of survey questions were distributed among respondents and analyzed using Statistical Package for Social Science (SPSS) based on the behavioral model called the multiple regression analysis. The correlation analysis shows that attitudes have a significant effect on the safety of pedestrians and other factors do not show significant results. However, the two-step regression analysis demonstrates that the intention has a strong relationship with behavior on pedestrian safety. In order to enhance the government efforts to mitigate road accidents, it is efficient to use an education as a medium which helps to change the attitude of road users in the country.

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Cold mix asphalt (CMA) is an eco-friendly sustainable asphalt mixture, mostly for asphalt surface... more Cold mix asphalt (CMA) is an eco-friendly sustainable asphalt mixture, mostly for asphalt surface treatments (ASTs). However, material compatibility and poor adhesion leading to high voids, moisture damage susceptibility, and weak early strength remain challenging. Efforts to solve this limitation is beamed towards binder improvement and modification with modifiers, adhesion promoters, or polymers. Other forms of AST mixture improvement entail supplementary cementitious reinforcing or pozzolanic agents in the form of by-products. In this study, the physio-mechanical and microstructural desirability of spent garnet for use as fine aggregate in CMA was explored. Spent garnet is a by-product of abrasive blasting, often produced in large quantities and disposed of in landfills. Often, spent garnet waste gets contaminated with toxic elements either during usage or in landfills. This study aimed to investigate the properties of Automatically (AG) and Manually generated (MG) spent garnet grades. The physio-mechanical, morphologic, and chemical parameters of spent garnet were assessed to achieve this aim. The result compared with relevant specifications on cold mixtures plus Jabatan Kerja Raya (JKR) requirement. Moreover, crystallinity and composition were studied using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and X-ray Fluorescence (XRF). The presence of toxic heavy metals that often contaminate spent garnet deposits in landfills was evaluated too. Results suggested that both AG and MG's high sand equivalent and least water absorption of 98 %, 89 %, and 0.14 %, 0.23 % accordingly, and can replace sand in CMA. However, MG spent garnet is not desirable for chemically sensitive materials. The AG garnet was found to be Pyrope while the MG spent garnet is largely Almandine garnet-the strongest form of garnet, including traces of other garnet forms.

Sustainability, 2022

Airports play a critical role in transporting goods and passengers and supporting the growth of t... more Airports play a critical role in transporting goods and passengers and supporting the growth of the world economy. Airports spend huge sums annually to maintain and improve pavement functions by expanding the runways, taxiways, and aprons, and perform routine maintenance and rehabilitation of the existing pavements. Besides the traditional direct costs, a comprehensive airport pavement management system should also consider indirect costs such as fuel, crew, passenger delay, aircraft maintenance, and loss of airport revenue when conducting a life-cycle cost analysis (LCCA). Engineers, managers, and stakeholders can make better decisions on the appropriate pavement maintenance and rehabilitation strategies by performing economic analyses of the direct and indirect costs. This study performed probabilistic and deterministic LCCA to contrast the effect of direct costs vis-a-vis indirect costs in airport pavement management. A case study found that indirect costs could contribute up to ...

Road Materials and Pavement Design, 2021

Civil Engineering Journal, 2021

High demand for asphalt binders in road construction verifies the need of finding alternative mat... more High demand for asphalt binders in road construction verifies the need of finding alternative materials through asphalt pavement recycling. This paper investigated the impact of different rejuvenators on the performance of an aged asphalt binder. Virgin Olive oil, virgin cooking oil, waste cooking oil, virgin engine oil, and waste engine oil were added to a 30/40 penetration grade aged asphalt binder at a fixed oil content of 4% for all types. The wet method was used to blend the rejuvenators and aged asphalt binder. The physical, rheological, and chemical properties of the rejuvenated asphalt binder were evaluated using several laboratory tests which include penetration, softening point, bleeding, loss on heating, storage stability, penetration index, ductility, viscosity, dynamic shear rheometer, and Fourier transform infrared spectroscopy. The outcomes of the physical properties showed that the olive, waste, and virgin cooking rejuvenators can restore the aged asphalt binder to a...

Applied Sciences, 2021

This study was conducted to investigate the effect of ageing on bitumen, before and after modific... more This study was conducted to investigate the effect of ageing on bitumen, before and after modification. Nano-clay modified bitumen (NCMB) was produced by adding nano-clay (NC) to 60/70 penetration grade bitumen; then, the binder was tested using conventional tests for properties such as penetration, softening point and viscosity. These tests were carried out on the modified binder before and after ageing. A rolling thin film oven (RTFO) was used to simulate short-term ageing (STA), and a pressure ageing vessel (PAV) was used to simulate long-term ageing (LTA) for the modified binder. After initial results showed an improvement for the modified bitumen regarding the effect of ageing, the investigation continued using Fourier transform infrared spectroscopy (FTIR), where the microstructure distribution of the modified binder before and after ageing was observed. Finally, there was no doubt that the effect of ageing on mixtures should be investigated. For this step, the indirect tensil...

Sustainability, 2021

Reclaimed asphalt pavement (RAP) has received much attention recently due to its increased use in... more Reclaimed asphalt pavement (RAP) has received much attention recently due to its increased use in hot mix asphalt (HMA) pavements to enhance pavement sustainability. The use of aged asphalt in RAP, which is highly oxidised and has lost its properties due to exposure to traffic loads and climatic conditions throughout its lifespan, can cause asphalt mixtures to stiffen and embrittle, thus negatively affecting the behaviour of asphalt mixtures. This issue may be resolved by including rejuvenating agents that can restore both physical and rheological properties of aged asphalt by increasing maltene fractions and decreasing asphaltene. However, the high restoration capacity of any kind of rejuvenating agent does not assure the durability of restored aged asphalt. This study explored the performance and durability of rejuvenated asphalt mixtures embedded with several types of rejuvenators identified from the extensive literature review. The study serves as a significant reference to pred...

Journal of Rehabilitation in Civil Engineering, 2021

The compacting and mixing processes involving hot mix asphalt during asphalt production can lead ... more The compacting and mixing processes involving hot mix asphalt during asphalt production can lead to air pollution as a result of a high volatile organic compound. An alternative solution that can reduce greenhouse gas emissions is by using warm-mix asphalt (WMA). A proper application of additives to the WMA can improve the asphalt mixture's strength, durability, and workability. In this study, a 60/70 grade asphalt binder was added with 5% of crumb rubber (CR) and three different WMA additives at the recommended dosages, namely Sasobit, Cecabase, and Rediset. The wet method was used to blend the additives with virgin asphalt binders. The mixing and compacting temperatures were set at 135°C and 125°C, respectively, to mix the asphalt mixture. Mechanical performance tests were performed to evaluate the impact of WAM additives with CR on asphalt mixture. Based on the results, all the modified asphalt mixtures showed a better mechanical performance than the virgin asphalt mixture in...