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Get the mix right

THE ready-mixed concrete business is one of the most aggressive sectors in an increasingly competitive construction industry.

That ready-mix firms have a history of forming cartels is arguably more to do with the volatility of the market than with any corruption in the business.

If you are trying to avoid selling on the basis of the cheapest price, you have to offer the customer a little bit more than just a load of concrete.

You have to remember that we are dealing with an industry that is not making any money, says Brian Malyon, managing director of leading ready- mix supplier RMC Transite.

That can lead to trouble. Despite the increasing emphasis on quality in the industry, some sites are happy to go to the cheaper operators, which may not be reliable.

'One of the problems with our industry is that the barriers to entry are quite small. You do not have to be a member of QSRMC (the Quality Scheme for Ready Mixed Concrete) to set up a plant,' says Mr Malyon.

QSRMC was set up as a specialist certification body over a decade ago and achieved accreditation from the Department of Trade and Industry as a fully independent body in 1988. It provides third-party assessment of a ready-mixed firms quality procedures and specifications. Contractors can complain to QSRMC if they think a registered ready-mix firm has given shoddy service.

But it does cost money to get QSRMC accreditation and this, among other things, is reflected in the price of the product. Some specifications do insist that the ready-mix supplier is QSRMC accredited, but some do not. Surprisingly, local authorities often choose to use non-accredited firms, says Mr Malyon, and it is a habit which the big ready-mix players are constantly lobbying to stop.

On the other hand, there are many construction firms which do see the benefits of using a big-name firm, says RMC Transites sales manager, Dave Foster.

'People take for granted that they will get what we say we are going to supply,' he says.

Service and quality become as important as price when looking at a project in its entirety.

Before a contract is negotiated, price tends to be the main issue, but once the contract is up and running, service becomes the most important factor, he explains.

Its no good having 20 to 30 men on site if the concrete does not turn up. Standing around used to be a hidden cost but now they are having to look at the whole project and these costs are now being taken into account.

And he adds that, once a contract comes to an end, quality is the main concern.

So how does a firm like RMC Transite make sure that its customers get value for money?

RMC Transite is the biggest of RMCs regional ready-mixed firms, with 31 batching plants in Northamptonshire, Bedfordshire, Buckinghamshire, Oxfordshire, Berkshire and Hertfordshire. It has 81 concrete wagons. The head office handles enquiries relating to about 4,000 contracts a year.

Sometimes there will be up to a dozen contractors asking for prices on the same job. Each enquiry has to be checked by one of two technical readers to make sure that the mix specifications make sense they arrive in all shapes and forms. All the details go onto a computer system so that prices can be added and a quotation sent out.

Additional orders from up-and-running contracts set off warning bells if the mix in question has not gone to that site before, and these, too, are referred to the technical checkers.

Once an order is placed, the contract information goes off to two further systems, the laboratory and the delivery offices.

Deliveries from all the batching plants are co-ordinated through the two delivery offices, which are linked by computer to the plants in their area. In any one month they might service 600 jobs with 800 to 900 different mixes. At the moment, they are dealing with 2,100 live sites.

The delivery office co-ordinates deliveries to sites. The system allows for any member of staff to deal with any order. Few loads have to travel further than 13 km to site.

This is no easy task, when you consider that 25 per cent of orders are received on the very day the site wants delivery; 20 per cent of all orders that come in are provisional; and 20 per cent of daily output is additional loads under-ordering is the norm.

The computer system shows the orders for that day for each plant and which are going out. It even shows where the wagons are: in the yard, being loaded or out on delivery.

At the plant, an order is received and batching begins. Three of the plants have computer controlled batching the code for a particular mix is entered into the plant computer and off it goes.

Computer control speeds the process up, especially when more than one site is getting concrete at the same time. The system can store data about three mixes at a time one being mixed, one in the weigh hoppers and one in memory. Even when the concrete has made it to site, that is not the end of the story. The contractor needs to know that the concrete is up to scratch, so testing of concrete cubes is next.

This is an area which has long been a bone of contention between supplier and contractor.

Contractors have been known to say that the cubes the suppliers tested had been thrown around in the back of a van, altering the concretes properties. Suppliers might say the contractors were not keeping the cubes under controlled conditions.

The van problem, at least, looks to have been resolved. Regulations introduced last year mean that ready-mix firms must have anti-vibration devices in the back of their vans.

While that should help keep the customer happy, the testing is not only to demonstrate to the customer that the concrete conforms to the specification, it is part of an on-going analysis which allows RMC Transite to regulate quality of concrete.

In the laboratory at head office in London Colney, RMC crushes 500 concrete cubes a week to check their compressive strengths. These and other test results are fed into a cumulative analysis programme on the computer.

Laboratory manager David Collins says this information is of vital importance.

It is the cornerstone of concrete design. If we have a problem, we would check the mix design and, if necessary, go back and redesign the mix, he says.

'The fundamental problem we have is that we supply the concrete by volume but measure by weight, so we are constantly checking that we are producing the volume we are claiming,' he says.

Variations in the aggregate, caused, for example, by an ironstone seam at the quarry, cause density fluctuations. But these are very rare, says Mr Collins.

'The density is remarkably constant within plus or minus 30 kg per cubic metre,' he says.

RMC Transite is equally confident that its systems are effective in delivering a quality product. Only one complaint has come via QSRMC in the past three years because most problems are sorted out between RMC and the contractor.

If we make a mistake, we tell the customer, says Mr Foster.

The unreliability of ready-mix deliveries is the cause of many a contractors grumble. But is off-site batching as hit-and-miss as some would have us believe? Kristina Smith visited one of RMCs ready- mix firms to see for herself . . . but once the contract is up and running, service becomes the most important factor

Dave Foster, RMC Transite

Before a contract is negotiated, price tends to be the main issue . . .