Burcot & Clifton Hampden for the Protection of the River Thames
What is a gravel pit?
A gravel pit is an open-cast quarry for the extraction of gravel. Gravel, and its finer-grained cousin, sand, is often found in floodplains, where in the past, the action of a river had led to its accumulation.
There are numerous examples of gravel pits in the Thames Valley, both old, abandoned workings and quarries where extraction is still carried out. For example, there is a large, active gravel pit between Didcot, Sutton Courtenay and Appleford, as shown in the image below. Gravel pits may be worked for over 20 years. The gravel and sand is dug from the ground and is then sorted (graded) by size.
What is gravel used for?
Gravel and sand are used extensively in pretty much all aspects of construction, including houses and roads. Both sand and gravel are also ingredients in the manufacture of concrete.
What is a concrete processing plant?
Concrete is a composite of sand and gravel bound together with cement and water. A concrete processing plant will mix together sand, gravel and cement. The concrete processing plant that is proposed for the site will be able to source the sand and gravel from the gravel pit but will need to import lorry loads of cement.
When water is added to the concrete mix, a semi-liquid is produced that workers can shape (typically by pouring it into a form). The concrete then solidifies and hardens to rock-hard strength through a chemical reaction. Further lorry movements will be then be required to export the mixed concrete.