Preload Tanks Require Specialist Investigation And Repair Techniques

摘要

Preload tanks, sometimes referred to as prestressed or wire-wound tanks, have been widely used in the water industry since the early 1950s, primarily as water reservoirs. The use of high-tensile steel tendons, or cables, to impart compressive forces into the structure, conferred the benefits of speed of construction, light weight and low cost.rnInstances of prestressing wire failure have been fairly common but it was not until December 1999, when the domed roof of one tank collapsed at Lanner Hill in Cornwall, that a catastrophic structural failure was reported. Since then, there have been further sudden and disastrous failures as such structures continue to deteriorate. The failures are presenting significant safety, environmental and financial risks to the water industry and have resulted in an initiative to inspect and repair these tensioned structures as a matter of urgency.rnAgainst this background, specialist main contractor Concrete Repairs Ltd (CRL) has developed specific techniques and site procedures for the safe investigation, repair and refurbishment of preload tanks. CRL Surveys, a division of CRL, has inspected in excess of 30 such tanks throughout the UK and is involved in a rolling programme of remedial works.