Influence of Asphalt Emulsion Inclusion on Fly Ash/Hydrated Lime Alkali-Activated Material

Supplementary cementitious materials have been widely used to reduce the greenhouse gas emissions caused by ordinary Portland cement (OPC), including in the construction of road bases. In addition, the use of OPC in road base stabilization is inefficient due to its moisture sensitivity and lack of flexibility. Therefore, this study investigates the effect of hybrid alkali-activated materials (H-AAM) on flexibility and water prevention when used as binders while proposing a new and sustainable material. A cationic asphalt emulsion (CAE) was applied to increase this cementless material’s resistance to moisture damage and flexibility. The physical properties and structural formation of this H-AAM, consisting of fly ash, hydrated lime, and sodium hydroxide, were examined. The results revealed that the addition of CAE decreased the material’s mechanical strength due to its hindrance of pozzolanic reactions and alkali activations. This study revealed decreases in the cementitious product’s peak in the x-ray diffraction analysis (XRD) tests and the number of tetrahedrons detected in the Fourier transform infrared spectroscopy analysis (FTIR) tests. The scanning electron microscope (SEM) images showed some signs of asphalt films surrounding hybrid alkali-activated particles and even some unreacted FA particles, indicating incomplete chemical reactions in the study material’s matrix. However, the H-AAM was still able to meet the minimum road base strength requirement of 1.72 MPa. Furthermore, the toughness and flexibility of the H-AAM were enhanced by CAE. Notably, adding 10% and 20% CAE by weight to the hybrid alkali-activated binder produced a significant advantage in terms of water absorption, which can be explained by its influence on the material’s consolidation of its matrices, resulting in significant void reductions. Hence, the outcomes of this study might reveal an opportunity for developing a new stabilizing agent for road bases with water-prevention properties and flexibility that remains faithful to the green construction material concept.

Performance Comparison of Asphalt Emulsion Stabilized Granular Base Modified with Cement or Asphaltenes

Asphalt emulsion is a common material used for pavement base course stabilization, and cement is usually added as an active filler to improve the stability of asphalt emulsion mixtures further. However, using cement in these mixes has several drawbacks, including high material costs and environmental issues. On the other hand, asphaltenes is a waste by product derived from the processing of Alberta oil-sands bitumen that could be used for the same purpose. This investigation compares the impact of cement and asphaltenes as additives to asphalt emulsion-stabilized layers. To compare the performance properties, cement- and asphaltenes-modified mixtures are prepared at different concentrations. The performance properties of the modified mixtures are investigated by conducting a series of tests including Marshall stability, indirect tensile strength, IDEAL-CT, and tensile strength ratio. In addition, to evaluate low-temperature cracking resistance of the mixtures, indirect tensile strength test is conducted at 0 °C and −10 °C.

Analysis of the Impact of Redispersible Polymer Powder on the Water and Frost Resistance of Cold-Recycled Mixture with Bitumen Emulsion

The subject of the research presented in the article is the assessment of the effect of redispersible polymer powder (RPP) on water and frost resistance of a cold-recycled mixture with bitumen emulsion (BE-CRM). The article presents the results of research on the influence of polymer powder EVA based on polymer (polyethylene-co-vinyl acetate) on the properties of BE-RCM. The impact analysis was determined using the assumptions of the Box-Behnken experiment plan in which three components are controlled. In this case, the variables were the content of: polymer, cement and asphalt emulsion. All ingredients were dosed with a step of 1.5% of the percentage share in the mixture composition. Polymer and Portland cement in an amount of 0.5% to 3.5%. On the other hand, the pure asphalt originating from the asphalt emulsion was 0.0%, 1.5% and 3.0%, respectively. The scope of the tests included the determination of: mixture density, void content (Vm), water absorption (nw), intermediate tensile strength (ITS), to water (TSR) as well as water and frost according to AASHTO T283.

Influence of Number of Collisions Towards Asphalt Emulsion Mixture Stability Using Marshall Method (SNI 06-2489-1991)

The development of road construction in Indonesia recently increased. This resulted in demand of asphalt, which is one of the materials used in the pavement mix has also increased. Aspalt emulsion in Indonesia have been applied, but only to the adhesive layer and the absorption layer. The Public Works Department of the Directorate General Bina Marga has issued several guidelines to guide the implementation of cold mix asphalt work. The use of emulsion asphalt mixture technology which has a low temperature will reduce emissions, reduce the amount of energy consumption, and avoid oxidation. This study aims to analyze the value of the optimum asphalt content (KAO) mixture of emulsion asphalt CSS-1h and to analyze the effect of the number of collisions on the stability of the emulsion asphalt mixture. The results show that based on the relationship between the emulsion asphalt content and all Marshall and volumetric parameters, the optimum residual asphalt content is obtained. The emulsion is 5.5%. The impact of the collision on the stability value increases with the number of collisions. This test results in stability values of 1223.5 kg, 1373 kg and 1401.1 kg for normal specimens while for immersed test objects the remaining stability values are 51.7 kg, 59 kg, 68.2 kg. Based on the values obtained, this test is declared to meet the specifications for the cold mix emulsion asphalt.