Rural Roads: Which is better, concrete or blocks paving?

By Goyan Dias-June 22, 2015

We are aware that the former government commenced a rural road concreting programme in year 2005. We all thought because of longevity of concrete pavements, the rural mobility burden prevailed so far would be resolved but after completing about 2500Km, by year 2009 the concreting programme was terminated, instead it was replaced with cement block paving, and at the moment rural roads pavements are being carried out using these interlocking blocks, made out of cement and sand.

CONCRETE PAVEMENTS

Reason for immediate termination of concrete pavement works was not that concrete pavements were not suitable, for our rural roads, but due to the bad engineering governance executed over the whole process, disregarding the accepted designs and construction standards. If the concrete pavements had been done as per the designs provided they would have had life spans of 30-40 years without any sort of maintenance burden, thus confirming that the concrete pavement is the least life cycle cost pavements option for our rural roads. When the present status of completed concrete pavements are considered none of these had been done in accordance with the designs provided, as a result almost all concrete pavements have failed structurally. In order to rectify the situation authorities now seem to be overlaying concrete pavements with asphalt concrete (Figure 01) or dumping asphalt to patch out holes. By now certainly we have been the world’s first nation to have amazing pavements as shown in figures 1,2 & 3 respectively.

Between 2010 and 2011 newspapers were flooded with public complains, like the one illustrated in figure 04 and 05. These news items demonstrate the status of engineering governance.

According to information available the estimated cost for 100m length of concrete pavement is Rs.0.5m,; this means per km it is Rs.5.0m. In reality what we have experienced is that the structural life of most of the pavements had come to an end within first two years, thus resulting a life cycle cost of 2.5m per km per year.

BLOCK PAVED PAVEMENTS

Blocks being produced at a central location it has been possible to maintain the required compressive strength and other quality standards, as a result not like in the case of on site mixed and poured concrete, the block paved pavements seem relatively satisfactory for the moment, but it would have been better if the authorities had followed the design provided by RDA. Unfortunately, because of this reason blocks paved pavements experiences settlements, point depressions, drainage deficiencies, all these have caused due to not adhering to the approved design. Yet compared with concrete pavements, blocks paved roads seem quite satisfactory. Other obvious advantages of block paved roads are cracks, point settlements won’t get propagated because blocks are inter blocked.

It is learned that the present administration is planning to readopt concreting option again instead of block paving. Carry out a scientific analysis and arrive at a decision. We all need to keep in mind that it is not the designs that have gone wrong but the way it is being done, due to political interference.