This dataset contains fibre-optic strain and temperature readings taken from two pre-stressed concrete beams on the Nine Wells road-over-rail bridge, located to the south of Cambridge. Each of these beams was instrumented with three fibre-optic cables prior to pouring of the concrete. One of the cables is used to measure strains caused by temperature, while the other two are sensitive to both mechanical strain and temperature strain. Readings were taken on various dates in July and August 2008. Readings were taken using a Yokogawa AQ8603 Optical Fibre Strain Analyser. The raw output of this analyser uses a proprietry format. Rather than provide data in this format, the data has been exported into Microsoft Excel and is provided as both Excel's native (.xlsx) format and also in OpenDocument Spreadsheet (.ods) format. One spreadsheet is provided for each beam. Within each spreadsheet file there is one sheet labelled 'Raw Strains' containing the exported output from the Yokogawa analyser for each of the three fibre-optic cables on each of several days. The remaining sheets contain processed data for each of the fibres for each day.