Swallownest Shotcrete

Natural Cement Distribution Ltd. recently received an enquiry for advise on the use of their natural cement based binder materials for either grouting or pressure pointing from EarthTec/Morrison regarding their contract at Swallownest.

This project was being carried out on behalf of Railtrack and involved the refurbishment of an Old brick culvert running beneath a live railway line.Site agent for the contractor Russell Grimbley also pointed out another problem which involved construction of wing walls and that using conventional methods of shuttering and pouring concrete would require a programme period of 17 days in total to complete these works and it was valuable programme time that the contractor could not afford to lose.

Following discussions it was decided that the contractor would utilise a NCD dry sprayed concrete with an 8mm aggregate.

Mr Grimbley told NATM : "This was a radical approach to the traditional construction methods, however as it was going to save us 15 days working time it was a method well worth trying."

A potential problem may have reared its head; trying to find skilled operatives in such a short space of time to apply the dry shotcrete mix. Therefore NCD’s Technical Engineer Ian Armitage gave a prep talk and undertook the training of two "operatives".

Operative Jim Coyle explained: "It was an easy introduction to sprayed concrete, and I was a bit dubious at first as this was obviously my first time, but the technical advice was good and I wouldn’t mind doing this type of work again."

The work was completed within the stated two days.