Weber Hybrid Cement Technology solves manhole bedding problems
13 07 2011
Two new products that include the latest Hybrid Cement Technology added to the Weber range of specialised construction mortars, now provide the total solution for manhole installation and renovation for nationwide utilities and eliminate the regular collapses caused by traffic loading and climatic damage.
The Weber Highway Ironwork Bedding System meets the requirements established by the Highways Agency Guidance Notes HA 104/09 and HD 27/04. webercem 104 mortar and webercem pyracrete have been tested and are fully compliant with these specifications. Many contractors are starting to use these products in new manhole constructions and for much needed repairs to meet utility customers’ adopted standards.
A major failure of inspection chamber access covers is the collapse of the frame bedding material caused by repeated loading fatigue coupled with frost attack. Safety and damage claims have resulted from collapsed manholes and there is increasing demand by utilities for a fast, reliable and durable repair system. The new Weber Highway Ironwork Bedding System meets this challenge and provides the perfect consistency to support even heavyweight frames.
Weber’s iron-frame bedding and infill products develop compressive strength of 20N/mm² within two hours of application and exceed 30N/mm² in three hours. webercem 104 mortar, the first mortar incorporating Hybrid Cement Technology was specially developed for manhole frame bedding. It gives a useful working time enabling full bedding buts sets rapidly thereafter. This product has good “squeezability” enabling accurate level alignment.
webercem pyracrete is a cement-based single component concrete used for infilling around the cover frames that sets in 10 minutes. All Weber bedding and repair products are low-shrink thus avoiding the risk of loose framework caused when traditional sand and cement dries. The latest products can be used all year round even in cold weather.
The complete Weber Highway Ironwork Bedding System features seven advanced technical products, four ironwork bedding products, the new webercem pyracrete rapid setting infill concrete and two types of pavement repair concrete. For manhole frame bedding the inventory includes the new webercem 104 mortar which sets in 15 minutes; webertec bedding mortar is a polyester resin based two part product with rapid 30 minute setting time; webercem pyrabed T60 and webercem pyrabed T90 with 60 and 90 minute setting time respectively. All these products exceed the Highways Agency standards of performance as does the new webercem pyracrete infill concrete with rapid 10 minute setting time. For concrete pavement repairs webercem pyrapatch is a polymer modified cement based single component product that sets in three hours and webercem pyratop is a cement based single component repair concrete that sets in six hours for fast repairs to concrete pavements.
Saint-Gobain Weber has a global reputation for technical concrete repair products of which the Highway Ironwork Bedding System is an increasingly important market category. Weber estimates that this sector of the utilities repair operations for manholes, cable ducts and pipework requires several thousand tonnes of specialised materials per year with a current estimated market sales value of nearly £10 million.