Characterizing Cold Bituminous Emulsion Mixtures Comprised of Palm Leaf Ash

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 materials.