Replacement Of Mineral Filler Research Articles

Introducing waste glass powder as a sustainable constituent in microsurfacing

This study examines the merits of using waste glass powder (WGP) in a microsurfacing mixture as a replacement for mineral filler. The replacement was done at 0%, 25%, 50%, 75%, and 100% by weight of the mineral filler. The performance of WGP-modified microsurfacing mixtures was evaluated through mix time test, wet cohesion test, wet track abrasion test, loaded wheel test-sand adhesion and loaded wheel test-horizontal and vertical displacement. The toxicity, chemical, and microstructural characteristics were respectively assessed using a toxicity characteristic leaching procedure, Fourier-transform infrared spectroscopy and field emission scanning electron microscopy. Performance analysis of the mixtures showed that an increase in WGP significantly enhanced the mixture's resistance against stripping, bleeding and rutting. The aggregate loss, sand adhesion, horizontal displacement and vertical displacement values at a WGP content of 75% were approximately 62%, 20%, 30% and 36% lower than the values of these parameters at a WGP content of 0%, respectively. Toxicity characteristic leaching tests were performed to compare the extent of heavy metals leaching from stockpiled WGP and from WGP-modified microsurfacing mixtures. It was found that heavy metals leaching from WGP-modified mixtures were 80% lower than heavy metals leaching from stockpiled WGP. The significant reduction in leachate could be attributed to the bitumen covering WGP and preventing WGP particles from exposure to water, as evidenced by microstructural analysis.

Evaluation of photocatalytic micro-surfacing mixture: road performance, vehicle exhaust gas degradation capacity and environmental impacts

To purify severe air pollution in traffic-intensive urban areas and tunnels, an innovative type of photocatalytic micro-surfacing mixture (PMM) was designed, which was enhanced by polypropylene (PP) fiber and nano-TiO2. In this work, the road performance of sixteen PMMs with the different contents of PP and nano-TiO2 were evaluated by wet-track abrasion test, wheel rutting deformation test and low-temperature splitting test. The vehicle exhaust (VE) gas degradation capacity of sixteen PMMs was characterized under ultraviolet (UV) light and visible light conditions. The life cycle assessment (LCA) methodology was applied to evaluate the environmental impact of PMM. The results showed that the road performances of PMM were improved with the increase of the PP fibers amount. The VE gas degradation capacity was significantly enhanced with the increase of nano-TiO2 amount. PMM with 0.2 wt% PP fibers and 60 wt% replacement of mineral filler with nano-TiO2 was a viable alternative to improve photocatalytic degradation of VE in pavement engineering. In addition, the modified micro-surfacing mixture facilitates a significant reduction in energy consumption and greenhouse gas emissions.

Modification of asphalt mixtures for cold regions using microencapsulated phase change materials

Phase change materials (PCMs) may be used to regulate the temperature of road surfaces to avoid low-temperature damages when asphalt materials become brittle and prone to cracking. With this in mind, different asphalt mixtures were modified with microencapsulated phase change materials (i.e. tetradecane) to assess their thermal benefits during the phase change process. Likewise, the effect on the mechanical performance of PCMs as a replacement of mineral filler was assessed. Special attention was paid to dry and wet modification processes for incorporating the PCMs into the mixtures. The results showed that PCM modifications are indeed able to slow down cooling and affect temperatures below zero. Approximately, a maximum of 2.5 °C offset was achieved under the tested cooling conditions compared to the unmodified reference specimens. Regarding the mechanical response at 0 °C and 10 °C, the results indicated that the PCM modification significantly reduces the stiffness of the material in comparison with the values obtained for the reference mixture.

Use of Rice Husk Ash and Domestic Plastic Wastes in Bituminous Concrete (BC)

This paper presents the experimental results on the utilization of Rice Hush Ash (RHA) and Domestic Plastic Wastes as a replacement for mineral filler and Optimum binder content (OBC) in bituminous concrete mixes. Bituminous concrete mixes containing Rice Husk Ash and Domestic Plastic Wastes at different amounts and control specimens were prepared in accordance to Marshall Mix design, and their performance on stability, flow and bulk density were evaluated. Optimum binder content (OBC) and voids analysis were also conducted to compare performance of Rice Husk Ash and Domestic Plastic Wastes at different contents. Results reveal that all Rice Husk Ash and Domestic Plastic Wastes mixes have satisfied the Public Works Department (PWD) specification and MORTH specification on wearing course in regard with Marshall Stability and Flow. This material is potentially to be used as partial or full substitution of mineral filler (stone dust) and Optimum binder content (OBC) in pavement construction. Modified bituminous mixes are expected to give higher life of surfacing depending upon degree of modification and type of additives used. The present study aims at developing bituminous mixes for the Bituminous Concrete (BC) Grade 1 incorporating the plastic wastes, waste tyre tubes and rice husk ash as partial replacement of the bitumen content. In this study, the Stability-Flow analysis for the various BC Grade 1 mixtures with modified binders and with different percentage replacement of bitumen with plastic wastes, waste tyre tubes and rice husk ash are reported.

Environmental aspects and pavement properties of red mud waste as the replacement of mineral filler in asphalt mixture

The red mud waste generated from the alumina refining industry, which remains high alkalinity and problematic pollutants, is occupying considerable land resource and causing significant environmental problems worldwide. Instead of landfills, the utilization of the red mud waste as a substitution of mineral filler in asphalt pavement mixtures has been investigated in this study. The physical and chemical properties of the red mud waste were first characterized. The experimental tests including softening point, penetration, dynamic shear rheometer (DSR) and multiple stress creep recovery (MSCR) were then conducted to evaluate the properties of asphalt mastic. Based on the results on leaching toxicity and radioactivity, the red mud waste had no risk to be used as a building material. Moreover, the addition of red mud waste can improve the stiffness and elasticity of asphalt mastic. The increased rutting parameter and the decreased accumulated creep strain were further found, especially the Sintering RM. In addition, the Sintering RM had the capability to improve the elastic recovery of asphalt mastic, while the Bayer RM had limited contribution to this behavior. Consequently, the red mud waste can be concerned as a secondary resource to replace the natural mineral filler for asphalt pavements.

Experimental investigation on related properties of asphalt mastic with activated coal gangue as alternative filler

To evaluate the feasibility of using activated coal gangue (ACG) as replacement of mineral filler in asphalt mixture, some properties of asphalt mastic containing ACG were investigated in this paper, compared with the traditional limestone mineral filler (LMF). The investigated mastic consisted of asphalt and filler at a mass ratio of 1:1. Cone penetration test (CPT), Dynamic Shear Rheometer test (DSR), Brookfield viscosity test (BVT) and Dynamic Mechanical Thermal Analysis (DMTA) were applied to research the shear resistance rheological property, rutting resistance, high-temperature viscosity characteristics and low-temperature property of asphalt mastic. With the application of scanning electron microscope (SEM) and Infrared Spectroscopy (IR), the mechanism of ACG imposed on asphalt mastic was analyzed. Results indicate the possibility of ACG as inorganic filler derived from solid waste to improve the performance of asphalt. The ACG has better effect on improving the shear strength and temperature sensitivity of asphalt mastic than LMF. Besides, ACG has positive effect on high-temperature properties while some negative effect on low-temperature properties of asphalt mastic. The results also indicate that the physical adsorption between the ACG filler and asphalt binder is the main mode of action.

Use of Ash in Hot Dense Mixtures

Bituminous ash produced by the oil industry is used in landfill in large quantities. Recycling ashes coming from the oil industry can have signifi-cant benefits for the environment and is an attractive option for highway construction because it saves material acquisition and disposal costs. An experimental study was undertaken to investigate the use of these ashes as a replacement for mineral filler in hot-mix asphalt concrete. Physical tests were performed on the bituminous ash to determine its gradation, specific gravity, and chemical composition. Two cases were considered for determining the ash proportion. To evaluate the effect of a reduction in asphalt binder, ash with a maximum particle size of 0.074 mm [i.e., passing the Number (No.) 200 sieve] was used as a replacement for the asphalt cement content at percentages of 0 (i.e., control mix), 5, 10, and 15 by total asphalt weight. Also, ash was used as a replacement of the fine aggregate at percentages of 0, 30, 50, and 70 by total aggregate weight. In both cases, the ash came from thermal desorption in the hydrocarbon processes. Mix design was accomplished according to the Marshall mix design method (ASTM D1559). The results of these studies showed that use of ash passing the No. 4 sieve improved asphalt concrete characteristics while it reduced the use of aggregates when the asphalt proportion was 4.5%. Likewise, use of 0.8% fine ash (i.e., finer than the No. 200 sieve) to reduce the asphalt content in the hot dense mixture also improved the performance of asphalt concrete.

Utilisation of Rice Husk Ash in Asphaltic Concrete Pavement

This paper presents the experimental results on the utilisation of Rice Hush Ash (RHA) as a replacement for mineral filler in asphaltic concrete pavement in Malaysia. Asphaltic concrete mixes containing RHA at different amounts and control specimens were prepared in accordance to Marshall Mix design, and their performance on stability, flow and bulk density were evaluated. Optimum binder content (OBC) and voids analysis were also conducted to compare performance of RHA at different contents. Results reveal that all RHA mixes have satisfied the Malaysian Public Works Department (JKR) specification on wearing course in regard with Marshall Stability and Flow, especially RHA-75. This material is potentially to be used as partial or fully substitution of mineral filler (stone dust) in pavement construction.

Utilization of recycled brick powder as alternative filler in asphalt mixture

The objective of this study is to investigate the use of recycled brick powder as replacement of mineral filler in asphalt mixture. A comparative study was carried out on the performance of two mixtures using recycled brick powder and limestone filler. The experimental performed were indirect tensile tests, static and dynamic creep tests, water sensitivity tests and fatigue tests. The results show that the mixtures prepared with recycled brick powder have better mechanical properties than the mixtures with limestone filler. Thus, it is promising to use recycled brick powder as mineral filler in asphalt mixture.

Use of sewage sludge ash in asphaltic paving mixes in hot regions

This paper presents the results of experiments on the utilization of sewage sludge ash as a replacement for mineral filler in asphaltic paving mixes used in Bahrain. The physical and chemical properties of the waste were studied. Asphaltic concrete mixes containing the waste and a control were prepared. Five percentages by weight of bitumen were employed in order to determine the optimum bitumen content suitable for the two mixes. The Marshall test method was used to evaluate the suitability of the waste as a filler in asphaltic concrete wearing courses. The parameters evaluated were the compacted mix density, the percentage of air voids in the mix, the percentage of voids in the mineral aggregate, the percentage of voids filled with bitumen, Marshall stability, and flow. Samples at optimum bitumen content were tested for stability and flow at 70 °C and 80 °C in order to assess the susceptibility of the mixes to the high temperatures prevailing in Bahrain. The results revealed that the minimum stability value of the Bahrain standard specification was satisfied by the waste specimens. Furthermore, at elevated temperatures, the waste mixes performed satisfactorily.