Characterizing Cold Bituminous Emulsion Mixtures Comprised of Palm Leaf Ash

Abstract Cold bitumen emulsion mixtures (CBEMs) are a promising substitute for hot mix asphalt (HMA) due to their low environmental impact, cost effectiveness, and low energy production costs. Nevertheless, conventional CBEM has some disadvantages, mainly related to the long curing time required to reach its full strength and its higher susceptibility to moisture. This paper reports the experimental test results of research that aimed to investigate and develop a new CBEM containing a waste biomass material, palm leaf ash (PLA), a waste material produced by burning palm leaves. The new CBEM was compared with a conventional cold mix (CCM) as a control. The tests to assess the mixtures’ mechanical properties were the Marshall test, indirect tensile strength, and wheel track test. Durability was evaluated by water sensitivity and aging tests. The results revealed noticeable improvements in the mechanical properties of the CBEMs comprising ordinary portland cement (OPC), and raised the possibility of replacing some of the OPC with PLA without compromising said improvements. Results have shown that the new CBEMs with PLA achieved outstanding results in comparison with traditional CBEM, with and without the addition of OPC. There was also a significant improvement in water sensitivity when using PLA. This paper therefore opens the door for the development of new CBEMs that have outstanding mechanical characteristics when made with biomass ash material

Investigating the Impact of Polymer and Portland Cement on the Crack Resistance of Half-Warm Bituminous Emulsion Mixtures

Cold mix asphalt (CMA) is emerging as an environmentally friendly alternative to traditional hot mix asphalt (HMA). It offers advantages such as lower costs, reduced energy demands, decreased environmental impacts, and improved safety aspects. Among the various types of CMA, the cold bitumen emulsion mixture (CBEM) stands out. The CBEM involves diluting bitumen through emulsification, resulting in lower bitumen viscosity. However, this process has certain drawbacks, including extended setting (curing) times, lower early strength, increased porosity, and susceptibility to moisture. This study focuses on enhancing CBEM properties through the utilization of low-energy heat techniques, such as microwave technology, and the incorporation of a polymeric additive, specifically acrylic. These innovations led to the development of a novel paving technology known as a half-warm bitumen emulsion mixture (HWBEM). The research was conducted in two phases. First, the study assessed the impact of low-energy heating on the CBEM. Subsequently, it explored the combined effects of low-energy heating and the addition of an acrylic polymer. CBEM samples containing ordinary Portland cement (OPC) as an active filler were utilized in the sample manufacturing process. The effectiveness of these techniques in enhancing crack resistance was evaluated by analysing the results of the indirect tensile strength test. Notably, CBEM samples containing an amount of 2.5% of acrylic polymer and OPC exhibited the highest resistance to cracking. Furthermore, significant improvements were observed in their volumetric and mechanical properties, comparable to those of HMA

Improving the Mechanical Properties and Durability of Cold Bitumen Emulsion Mixtures Using Waste Products and Microwave Heating Energy

Scientists have effectively demonstrated that the introduction of a waste product comprising cementitious chemical compositions can enhance the mechanical properties and durability of cold bitumen emulsion mixes (CBEMs). On the other hand, the high air void content of the CBEM mix remains a challenge that is considered unsatisfactory by paving engineers. As a result, this investigation highlights two major changes that were made. The first is the use of waste paper sludge ash (PSA) as a filler in CBEM instead of the conventional mineral filler (CMF). The second change was made to further improve the mixture by reducing the amount of CBEM air voids using microwave (MW) heating energy as a post-treatment method. When compared to typical hot mix asphalt (HMA), the new CBEMs showed great mechanical properties and durability. Moreover, the proposed method, using CBEMs, has lower environmental risks, is safer, and is more cost-effective than existing paving mix technologies. This study presents a method for controlling air voids within pavement specifications without affecting mechanical behaviour or generating additional environmental or economic considerations. When compared to typical mixtures, laboratory test results showed that MW-heating can enhance both the stiffness modulus and the air void content. Furthermore, these results revealed a minor reduction in creep stiffness and water sensitivity. Nevertheless, in terms of mechanical, volumetric, and economic properties, the suggested post-mix treatment was comparable to HMA. The findings point to the need to adopt CBEM post-heating approaches, particularly the MW treatment procedure

Innovative geopolymer-based cold asphalt emulsion mixture as eco-friendly material

In recent years, there has been a growing interest in cold asphalt emulsion mixture (CAEM) due to its numerous advantages, including reduced CO2 emissions, energy savings, and improved safety during construction and application. However, CAEM has often been considered inferior to hot mix asphalt (HMA) in terms of performance. To address this issue and achieve desirable performance characteristics, researchers have been exploring the modification of CAEM using high-cost additives like ordinary Portland cement. In this study, the focus was on investigating the effects of utilizing waste alkaline Ca(OH)2 solution, ground granulated blast-furnace slag (GGBFS), and calcium carbide residue (CCR) as modifiers to enhance the properties of CAEM. The aim was to develop an innovative geopolymer geopolymer-based cold asphalt emulsion mixture (GCAE). The results of the study revealed that the use of waste alkaline Ca(OH)2 solution led to an increase in early hydration, which was confirmed through scanning electron microscopy. Furthermore, the experimental findings demonstrated that waste alkaline Ca(OH)2 solution significantly contributed to the rapid development of early-age strength in GCAE. As a result, GCAE showed great potential for utilization in pavement applications, particularly for roads subjected to harsh service conditions involving moisture and temperature. By exploring these alternative modifiers, the study highlights a promising avenue for enhancing the performance of CAEM and potentially reducing the reliance on expensive additives like ordinary Portland cement. The development of GCAE has the potential to offer improved performance and durability in pavement applications, thus contributing to sustainable and efficient road infrastructure

A Sustainable Cold Mix Asphalt Mixture Comprising Paper Sludge Ash and Cement Kiln Dust

Concerns about the environment, the cost of energy, and safety mean that low-energy cold-mix asphalt materials are very interesting as a potential replacement for present-day hot mix asphalt. The main disadvantage of cold bituminous emulsion mixtures is their poor early life strength, meaning they require a long time to achieve mature strength. This research work aims to study the protentional utilization of waste and by-product materials as a filler in cold emulsion mixtures with mechanical properties comparable to those of traditional hot mix asphalt. Accordingly, cold mix asphalt was prepared to utilize paper sludge ash (PSA) and cement kiln dust (CKD) as a substitution for conventional mineral filler with percentages ranging from 0–6% and 0–4%, respectively. Test results have shown that the incorporation of such waste materials reflected a significant improvement in the mixture’s stiffness and strength evolution. The cementitious reactivity of PSA produces bonding inside the mixtures, while CKD is used as an additive to activate the hydration process of PSA. Therefore, based on the results, it will be easier to build cold mixtures by shortening the amount of time needed to reach full curing conditions

The development of a novel, microwave assisted, half-warm mixed asphalt

Global warming is an imminent threat that the world and its inhabitants have to confront. As such, it is the duty of the pavement industry as a contributor of greenhouse gas emissions, to pave the way by lowering its carbon footprint. It is vital that new measures are adopted in order to do so such as employing the use of emulsion-based mixtures (EBM). The problem with this is that the performance properties of such mixtures are inferior to that of traditional hot mix asphalts (HMAs). The air void content of EBM is very high and considered unacceptable by road engineers for application as a surface layer. That said, these mixtures are not only environmentally friendly but also boast ecological and economic advantages. An innovate approach was applied in this research by using a pre-compaction microwave processing technique to develop a novel, half-warm mix asphalt mixture (H-WM). This new mix was shown to have improved mechanical properties and lower air void content. EBM mixtures comprised of cementitious binary blended filler, were prepared using microwave heating applied over different lengths of time. Stiffness modulus, air voids content and temperature were used to establish the optimum microwave radiation time. The results indicated that 1.5 min of microwave processing decreased air void content from 8.92% to 7.12%. A 7% improvement in stiffness modulus was also found and the temperature was within lower limits (43°C). Hydration was accelerated by the microwave radiation, and the demulsification of bitumen emulsion was promoted. Microwave processing was found to have a positive impact on permanent deformation at elevated temperatures in comparison to the two reference HMAs used. It also proved to be an adequate technique to produce a fast-curing H-WM with lower air voids content. Water damage resistance for the microwaved H-WM (99%) is better than the reference HMA mixes. The findings of this study show that the novel half-warm asphalt mixture has superior properties in comparison to EBM

Estimating parking generation rate for Karbala holy city using multi-variables approach

Car parking planning, design, and management processes are very important to all cities and places to ensure efficient traffic system. Estimating the demand of car parking represents the significant start point for the success of these processes. Generally, there are many local and international estimating criteria, but such criteria need continuing update due to many reasons related to socioeconomic factors, lifestyle changes, development in technology, etc. Moreover, the majority of these criteria depend on single parameter for the estimation of parking demand; such as bed or employee for hospital, gross floor area or employee for office, and so on. The main aim of this research is to estimate the park generation rate for specific land uses depend on multivariable to increase the accuracy and limiting the effect of variation in parameters. Statistical analysis was conducted to create predicting models for each land use. The collected data was nominated for Karbala holy city, where different parameters are scaled for different city sectors. Groups of statistical models (i.e., simple, multi linear and nonlinear statistical models, and Weighted Linear Regression (WLR)) were used to create best representative relationship between the number of demands for car parking and multivariable parameters or factors affecting these lands used demands. Resulted statistical models were tested for best fit using statistical indices for model verification. Results disclose the significant of multivariable model compare with simple models. Also, WLR model shows it validity compare with multi-regression model for almost land use models. Consequently, for more accurate estimation the multi variable models are initiated with continuous need for updating

The effect of waste low-density polyethylene on the mechanical properties of thin asphalt overlay

In recent years, there has been a huge demand for innovative methods to upcycle waste materials. This study aims to explore and evaluate the effect of using waste low-density polyethylene (w-LDPE), collected from waste plastic bags for domestic purposes, on the mechanical properties of dense Thin Asphalt Overlay (TAO). Waste materials have been deemed appropriate in the development of asphalt pavement mixtures, due to the expected enhancement in mixture properties further to the reduction in cost and saving natural resources. Three dosages of w-LDPE were incorporated with asphalt binder: 2%, 4%, and 6%. Marshall stability and flow test, indirect tensile strength, creep compliance, skid resistance, wheel track, Cantabro abrasion loss and tensile strength ratio tests were carried out on both control and modified asphalt mixes to achieve the aim of the study. The results show a substantial enhancement in the performance of TAO modified with w-LDPE when compared to the control mix. The pre-eminent improvement was obtained in the creep compliance test, in which the creep compliance value decreased by 83% compared to the control mixture when using 6% of w-LDPE. This study indicated that using waste material is an effective method of asphalt modification that also contributes to promoting environmental sustainability

Developing a sustainable, post treated, half warm mix asphalt for structural surface layer

Sustainability and materials recycling have increasingly acquired importance in various aspects of life. It has well known that 95% of roads are paved with hot mix asphalt (HMA), their raw materials require a lot of energy to prepare and lead to the release of a considerable amount of CO2 into the environment. As a result, developing new technologies to prepare a new sustainable asphaltic mixture that consumes less energy and is eco-friendly becomes a necessity. This research aims to develop a sustainable half-warm asphalt mix by exposing the cold bituminous emulsion mixture (CBEM) to a post treatment using microwave energy technique, as well as utilising crushed glass waste as fine aggregate. The newly developed mix (half warm bituminous emulsion mixture, or HWBEM) is evaluated in terms of two main failure distress (cracking and rutting) using wheel track (WTT) and indirect tensile tolerance index, or cracking tolerance index (CT-index), in addition to the volumetric and durability evaluation in term of air voids content (AV) and retained Marshall stability test (RMS). Tests results regarding mechanical, volumetric, and durability properties indicated that the developed mixture was relatively comparable in some of the properties with referenced CBEM and superior in one aspect. Moreover, the sustainability aspect was achieved successfully by replacing a significant amount of virgin fine aggregate with the crushed waste glass. Based on the results of the test program, it can be said that the newly developed HWBEM incorporated waste glass can work as a structural surface layer

The future of eco-friendly cold mix asphalt

Road pavements are pivotal to the infrastructure, transportation and ultimate efficiency of both the public and the economy. However, they are undeniably having detrimental effects on an already compromised environment. Consequently, a re-think about road pavement construction materials is of paramount importance. Cold mix asphalt (CMA) is a low carbon manufacturing approach to the production of flexible pavement material that has proved to be very promising, both economically and ecologically. This technology allows the manufacture of mixtures at ambient temperatures without heating huge amounts of aggregates and bitumen, this decreasing CO2 emissions and saving energy. In spite of these positive impacts, CMA has a high sensitivity to traffic and environmental stresses due to the existence of water within the mixture, this of major concern to the industry. This study aims to review types of CMA and the main developments involved in cold bitumen emulsion mixture (CBEM) technology that can be used without decreasing in-service performance. This review also aims to provide a practical guide for the manufacture of bitumen emulsion and the design procedure of CBEM for the road pavements industry. Finally, it can be suggested that CMA is a crucial technique for pavement construction, as it provides acceptable performance alongside energy-saving and ecological objectives