TEL risk predictor

by Graham Ridout



An innovative system has been developed that allows clients to get an accurate prediction of the future maintenance and repair costs of their reinforced concrete structures, based on the degree of risk clients are prepared to accept over the durability of the structure.

The system, developed by Taywood Engineering Ltd (TEL), offers clients the chance to consider different durability characteristics of the structure at the design stage, and to calculate the likely upkeep costs dependant upon the level of risk they are prepared to manage.

TEL technical manager, Dr Phillip Bamforth, said that the system's software program predicts the service life and the deterioration rate of the structure based on the specification chosen for the concrete.

A wide range of factors that affect durability can be considered, including: different types of concrete; using chemical admixtures or additives like blastfurnace slag or pulverised fuel ash; replacing ordinary steel reinforcement with stainless steel bars; applying a protective coating to the finished concrete; or using controlled permeability formwork which eliminates blow holes and thereby gives a denser, more impermeable finish to the concrete.

The specification details are entered into the program which calculates the serviceability of the concrete, by modelling the selected specification against historical evidence of the way concrete ages in real life, combined with results of accelerated weathering experiments.

Bamforth said the program is able to give "fairly rapid scoping" so that different specifications, with differing service lives, can be considered by a client or specifier.

At the same time, clients get a breakdown of the anticipated annual repair costs, coupled with the current rate for repairs. Once the system is up and running, it will be possible to predict the performance of the repairs and also give clients a choice of repair methods tailored made to their needs.