Spreadsheet - Ciria C660

As concrete hydrates, it generates heat. In massive pours, this heat causes expansion, followed by contraction as the concrete cools. If not managed correctly, this thermal cycle leads to cracking. While the CIRIA C660 publication provides the theoretical framework and equations to predict and mitigate this cracking, the calculations are complex, iterative, and prone to human error if done by hand.

The guide addresses a specific physical phenomenon: .

This article explores the significance of the CIRIA C660 spreadsheet, breaking down its functionality, the engineering principles behind it, and how modern engineers can utilize it to design durable, watertight concrete structures. Before diving into the spreadsheet itself, it is essential to understand the publication it is based on. CIRIA (Construction Industry Research and Information Association) released C660 in 2007 as an update to the previous R91 guide. It quickly became the UK industry standard and is widely recognized internationally for calculating the risk of early-age thermal cracking.