Trialling of new HBM takes place


Paul Smith (left) and OCL’s Managing Director Stuart Gready at Butser trialling the HBM

TJ have partnered with OCL Regeneration to create and produce a new hydraulic bound material (HBM), which has recently been trialled to test its strength. The material will be largely made up of Rock Chalk – 90%+ – which will be excavated from TJ’s Butser Quarry, crushed and then mixed with water and cement at OCL’s mixing plant.

The purpose of the trial was to establish the optimum moisture content of the material. This was done by changing the mixing ratios of the chalk, water and cement and testing each combination separately so that the strength of each option can be calculated and analysed.

The various different ratioed samples of material were poured into separate 15cm metal cubes and the strength of each will be tested at 7, 14 and 28 days so that analysis can be carried out. This will also ensure that the end material matches the strict specification requirements that must be met.

The target is that when the trial is complete, it will achieve Clause 840 Specification for Highways, which will make it an approved sub-base material. The intended purpose for this will be as a sub-base for new highways infrastructure; namely it will be laid under the asphalt layer of the road.

The trials took place on 30 May so with the 7, 14 and 28-day tests, the final results should be back at the end of June. After that we will officially be able to offer the material for sale, with the official launch expected to be at the end of July.

HBM strength testing

OCL Regeneration specialise in aggregate recycling and work from their depots in South and Central England and on a national mobile basis. They own and operate mobile plant suitable for crushing / screening and ex-situ mixing with our mobile foamed bitumen and stabilisation plants.

OCL are fully quality assured and competency-accredited, with their main focus being on health and safety and value engineering for sustainable solutions to the everyday requirements of the construction industry.

Paul Smith, Commercial and Operations Manager said: “The idea to blend chalk with other materials was born a couple of years ago and myself and Steve Grant, TJ’s Commercial Director, have been tentatively working on this for the past 6-12 months. The supply of primary aggregates that have historically been used as a sub-base for highways is in short supply in the local area, which gave us this prime opportunity to create an HBM that will utilise the materials we have available locally. The result will be a strong, high quality product that will be readily available and easily transportable.”

This HBM should also prove to be cost effective as savings are likely to be made based on the volume of materials required versus traditional materials. Also, as the material is sourced and produced locally, transportation costs will also be less.

Keep your eye on our website for confirmation of availability of this HBM as well as the other aggregates we offer.

Top Photo: Paul Smith (left) and OCL’s Managing Director Stuart Gready at Butser trialling the HBM