Road infrastructure is one of the main foundations of modern development. Well-designed roads not only function as routes for the mobility of people and goods, but also determine economic efficiency, transportation safety, and environmental sustainability. As traffic volumes increase and transportation needs become more complex, the challenge of designing road pavements that are strong, durable, and environmentally friendly continues to grow.
In this context, the scientific study entitled Experimental Investigation on Mechanical Performance of High-Porous Rubberized Asphalt Pavement Grouted with ECC Mortar presents an innovative approach to the development of road pavement materials. The study was authored by Muhammad Aswin, Musa Adamu, M. S. Liew, and Yasser E. Ibrahim, who collectively explored the potential of composite technology to improve the mechanical performance and durability of modern road pavements.
Among the authors, Muhammad Aswin played a significant role in formulating a research approach that integrates material engineering, pavement technology, and the utilization of environmentally friendly materials. This research not only focuses on enhancing the mechanical strength of road pavements but also embraces sustainability principles through the use of industrial waste materials and pavement structural designs that are more adaptive to environmental conditions.
The study originates from a classic issue in transportation engineering: the limited durability of certain types of conventional road pavements. One widely used type is Open-Graded Porous Asphalt (OGPA), an asphalt mixture with high porosity that allows rainwater to infiltrate into the pavement layer. This technology is known to improve driving safety by reducing surface water accumulation and lowering tire–road noise.
However, OGPA has significant drawbacks. Its porous structure makes the voids within the pavement susceptible to being filled with dust, soil, or other particles during service life. The accumulation of such materials can reduce drainage performance and accelerate structural deterioration. In addition, the structural stability of OGPA is relatively lower compared to other pavement types, requiring more intensive maintenance.
Addressing these issues, Muhammad Aswin and the research team developed a new concept in pavement design: high-porous asphalt pavement reinforced with engineered cementitious composites (ECC) mortar. This concept aims to create a composite pavement system that maintains high porosity for drainage functions while enhancing structural strength through void filling using ECC mortar. This approach resulted in two types of composite pavement structures examined in the study, namely HAGE (High-Porous Asphalt Grouted with ECC) and HRGE (High-Porous Rubberized Asphalt Grouted with ECC). Both systems combine a porous crushed stone asphalt framework with ECC mortar as a filler material that possesses superior mechanical properties compared to conventional concrete.
ECC itself is a cement-based composite material designed to exhibit high deformability and improved crack resistance compared to ordinary concrete. This material is known for its high compressive strength as well as its ability to sustain much greater tensile strain than conventional concrete.
In this study, ECC mortar was used as a grouting material to fill the voids within the porous asphalt framework. This process produced a composite structure that is denser and stronger than an asphalt framework without mortar filling. One innovative aspect of the research is the use of crumb rubber—rubber particles recycled from waste tires—as an asphalt modifier. The incorporation of crumb rubber not only enhances the elasticity of the asphalt material but also contributes to the productive utilization of industrial waste.
In addition to crumb rubber, the study also utilized palm shell ash (PSA) as an additive in the ECC mortar mixture. PSA is a by-product of the palm oil industry with a high silica content, enabling it to function as a pozzolanic material in cement hydration. The use of PSA allows for reduced cement consumption while enhancing the sustainability of construction materials. By combining crumb rubber and palm shell ash in the material design, the study demonstrates a material engineering approach that focuses not only on technical performance but also on environmental sustainability.
To evaluate the performance of the developed pavement structures, Muhammad Aswin and the research team conducted a comprehensive series of laboratory tests. These included evaluations of the fresh properties of ECC mortar, compressive strength tests, flexural strength tests, impact resistance tests, and resistance to high temperatures or fire. The test results showed that porous asphalt frameworks without grouting exhibited very low compressive strength. However, after the voids were filled with ECC mortar, the compressive strength increased significantly. HAGE specimens showed continuous increases in compressive strength with material age, while HRGE specimens exhibited a better combination of strength and flexibility due to the presence of crumb rubber.
In addition, flexural strength testing also demonstrated improved structural performance as the mortar curing progressed. The ability of the composite structure to withstand flexural loads indicates its potential application in roads subjected to heavy traffic loads. Another important finding was the ability of the composite pavement system to withstand high temperatures. ECC mortar proved capable of resisting heat exceeding 550°C, while also slowing heat propagation within the pavement structure. This high-temperature resistance is particularly relevant under extreme conditions such as vehicle fires or increased environmental temperatures due to climate change.
Beyond technical aspects, the study also has a strong sustainability dimension. By utilizing industrial waste materials such as crumb rubber and palm shell ash, the research demonstrates that recycled materials can be effectively integrated into modern infrastructure design. This approach aligns with global trends in civil engineering that increasingly emphasize the use of environmentally friendly materials and the reduction of carbon footprints in construction.
For Muhammad Aswin, this research not only contributes to the advancement of pavement material technology but also expands understanding of how composite systems can enhance the performance of transportation infrastructure. Through the integration of material engineering, construction technology, and sustainability principles, the study opens opportunities for the development of road pavement designs that are more durable and adaptive to diverse environmental conditions. In an academic context, this research enriches the literature on semi-flexible pavement technology, a pavement system that combines the flexible characteristics of asphalt with the structural strength of cement-based materials.
The scientific contribution of Muhammad Aswin and the research team demonstrates how a multidisciplinary approach can generate innovations relevant to future infrastructure needs. By integrating principles of material engineering, structural analysis, and environmental sustainability, this study provides a strong scientific foundation for the development of next-generation road pavement technologies.
For Universitas Sumatera Utara, the involvement of Muhammad Aswin as a researcher in this study reflects the active contribution of academics in addressing the increasingly complex challenges of infrastructure development. This research not only strengthens USU’s position in the fields of civil engineering and material engineering but also demonstrates that academic innovation can produce tangible solutions for sustainable development needs.
