PWD to test lime in road construction to prevent rain damage

THIRUVANANTHAPURAM: The Public Works Department (PWD) is set to launch a trial using lime mixed with tar to increase the durability of roads. The initial experiment will take place on the Vazhuthacaud–Jagathy stretch in Thiruvananthapuram. If the results are positive, the technique will be expanded statewide. In the new mix, 2% lime will be added to the tar.

Studies by the Kerala Highway Research Institute and the University of Kerala’s Department of Geology found that one major reason for road damage during the monsoon is the acidity present in the metal used for road construction.

According to a moisture sensitivity study, adding 2% hydrated lime or 3% cement can neutralise the acidic nature of the metal and strengthen its bond with bitumen, helping to prevent moisture-related damage.

Following this, quality engineers of the PWD were given special training at the Highway Research Institute. Tender procedures for constructing the first such road in the capital will begin soon.

For the initial phase of the study, samples were collected from quarries in Thiruvananthapuram, Kollam, and Pathanamthitta districts. In the second phase, samples will be collected from quarries in Kottayam, Ernakulam, Thrissur, Malappuram, Wayanad, Kozhikode, Kannur, and Kasaragod districts.