Highway Research Record

II. PAVEMENT ENGINEERING AND PAVING MATERIALS
1. SOIL STABILISATION, LOW GRADE MATERIALS AND LOW VOLUME ROADS
NEW PROJECTS
Use of Fly Ash for Rural Road Construction near Dandeli, Karnataka

Date of Start: May 2004
(i) Central Road Research Institute, New Delhi (R, I)
(ii) Rajiv Gandhi Rural Housing Corporation Ltd, Karnataka (S)

Scope and objectives

The objective of the project was to provide guidance to engineers from Rajiv Gandhi Rural Housing Corporation (RGRHCL), Karnataka regarding construction methodology to be adopted and quality control tests to be done during road construction using fly ash by taking up construction of demonstration road stretch at Dandeli in Karnataka.

Methodology
CRRI and RGRHCL engineers undertook a joint field visit and identified the road stretch to be taken up for demonstration project. This road stretch formed a part of road network being constructed by RGRHCL to serve as colony roads for construction of housing meant for rural population based on characterisation of fly ash and other construction materials, the design of pavement was carried out at CRRI. Subsequently construction work was taken up. Fly ash collected in dry form from ESP of captive power plant of Dandeli paper mills was used. Fly ash was conditioned at the plant and transported to the site in covered trucks. GSB are not available easily in and around Dandeli. As the area has vast aggregates for dense forests, quarrying for GSB would disturb the fragile environment of the area. Hence fly ash, a waste material that is available locally at nearby power plant, was used to replace GSB. Fly ash was stabilized using 5 percent cement. Labour oriented techniques were adopted for stabilization. Stacking, mixing and laying were done manually and rolling was done using an 8-10 ton static roller. A layer of WBM Grade II was constructed above the stabilized layer. As a part of the project, a workshop was also organised to introduce techniques of fly ash usage. The stretch was recently inspected after the first monsoon and its performance was found to be good.

Conclusions
The project demonstrated that cement stabilized fly ash can be successfully used as a pavement layer as an alternate of GSB.

Significance/ Utilization Potential
The project would help the engineers from RGRHCL to undertake similar works in road projects being undertaken by them.

Limitations
At some places, the transportation cost of fly ash would make it economically unviable.