RSTA Committee Reports
HIGH FRICTION SURFACING
The High Friction Surfacing Committee is finalising a Code of Practice aimed at providing new guidance to restore client confidence with regard to durability. The HFS market has been badly affected during the downturn with increasing input costs and deteriorating client perceptions over how long HFS systems can last. This new Code, when published later this year, will contain a new UK specification for calcined bauxite, will have client endorsement and will hopefully go a long-way to correct misconceptions and reverse the downward trend in the market.
The HFS Committee have recently re-drafted Clause 924 at the instigation of the Highways Agency. The revised draft clause places greater emphasis on using calcined bauxite aggregate and introduces a 5 year performance guarantee linked to the new code of practice.
A new one-day HFS training seminar was launched in May, hosted by Ennis Prismo in Chorley and attended by many client delegates. The feedback has been very positive and the course will be repeated in Durham on 1st December and next spring in the South East – venue to be confirmed.
The HFS Committee is also considering establishing a joint-industry apprenticeship scheme with RSMA funded by Construction Skills.
The Surface Dressing Committee is currently dealing with a number of important issues including: updating the Code of Practice; providing input in the CEN 5 year review of EN 12272-1; the rate of application of binder and chippings; capturing evidence of roads not potholing several years after being surface dressed. Contractors are also preparing their TAITs (Type Approval Installation Trials) which are a requirement of the incoming European Standard EN 12271 in January 2011.
The Slurry-Microsurfacing Committee are busy developing a new Code of Practice, unifying Sector Scheme 13a with 13b, and contributing to the CEN 5 year review of EN 12274 suite of test methods. Contractors are also preparing their TAITs for when the European Standard EN 12273 comes into effect in January 2011.
Over recent months, the Specialist Treatments Committee have elected a new chairman in Howard Cooke (Asphalt Reinforcement Services) and changed the committee name from Allied Industry Members. The new name is designed to provide more clarity to client bodies regarding the activities of this group.
Howard Cooke chaired his first meeting of the Committee on 5th July. He explained how he would like to encourage input from client bodies to ensure that the work carried out by this committee was embraced by the client and met their expectations.
The first meeting of the newly-formed RSTA Geosynthetics Sub-Committee, chaired by Howard Cooke of Asphalt Reinforcement Services, discussed the first edition of the ‘Code of Practice for the use of Geosynthetics in Bitumen Bound Layers’. The Code will provide highway authorities, designers and principal contractors with a thorough understanding of geosynthetics, their selection, use, laying techniques and applications.
Utilization of reinforcing geosynthetics in road pavements will delay or even prohibit reflection cracking. The correct deisgn will extend the surface life of asphalt pavements and reduce ongoing maintenance costs. Furthermore, they increase pavement structure resistance against frost heave or differential settlements. Geosynthetics also provide economic, environmental and traffic safety advantages. Reinforcing asphalts may provide thinner road structures and longer life cycles which result in savings of natural resources and prolonged service intervals. All this adds up to a cost effective solution for rehabilitation.
In addition to producing the Code, committee members are collating independent research material and performance evidence to demonstrate how the use of geosynthetics can improve whole live pavement costs. The first edition of the Code makes reference to the study carried out by R.I.L.E.M which includes case histories, laboratory and full-scale experiments, plus essential aspects related to installation procedures and design. The committee recognises the importance of installation and will examine working with the Sector 13 scheme to provide competent qualified operatives. When the Code is complete it is hoped to gain full endorsement by client bodies in order to improve standards and awareness of the need for high quality work.