Concrete testing. On your site.

It depends on the concrete specification and the workability class specified. Send the specification and we will confirm the appropriate method before the pour.

Hixtra can sample and make cubes on site to the specified method, with initial curing arranged before the cubes are transferred for further curing and testing.

Yes. Diamond core drilling can recover samples for laboratory testing. Tell us the location, dimensions, access and any services that need checking before drilling.

Same-day and next-day testing dates are available in many areas. The earlier we know the pour date, sampling frequency and testing ages, the more easily we can plan the visit.

Where a method sits within our accredited schedule the report will say so. Ask us to confirm the accreditation status of each test before booking.

A composite sample is taken as several increments spread through the discharge of the load, then remixed on a clean non-absorbent surface before any test begins. Sampling is usually carried out to BS EN 12350-1. Where the sample comes from matters, because the very start and the very end of a discharge are not representative. We agree the sampling point with you beforehand, whether that is at the truck or at the point of placement.

Slump measures the consistence, or workability, of fresh concrete, not its strength. The cone is filled and compacted in layers, lifted, and the drop in height measured, usually to BS EN 12350-2, then compared with the consistence class or target value in your specification. A result outside tolerance normally points to water content, admixture dosage or the time since batching rather than the mix itself. A collapse or shear slump is not a valid result and the test is repeated on a fresh portion.

The number comes from your specification rather than from a single national rule. Sampling rates are normally set by the project specification, or by the identity testing provisions in BS EN 206 and BS 8500, and are expressed as one sample per volume of concrete, per batch or per day's pour. Each sample usually yields at least two cubes for each test age, so a 7 and 28 day requirement doubles the count. Send us the specification and the pour volumes and we'll confirm the number.

Air content, fresh density and concrete temperature are the usual additions to a consistence test. Air content is commonly measured by the pressure method in BS EN 12350-7 and matters where the concrete has a freeze-thaw exposure requirement. Fresh density, usually to BS EN 12350-6, gives a yield and compaction check. Concrete and ambient temperature are recorded where the specification or the weather makes them relevant, and all of these can be carried out on the same sample during one visit.

We tell the site straight away, and the decision to accept or reject the load is yours. Our job is to test, record and report what the concrete did, not to accept or reject material on your behalf. The result, the time it was taken and the delivery ticket details all go into the record, including for a load that is sent back, so you and the supplier have the same account of what happened. Rejected loads are then a matter between you and the producer.

Yes, and it changes the concrete as well as the result. Water added after batching raises the water/cement ratio, which reduces strength and durability, and UK specifications commonly treat concrete that has had water added on site as non-conforming. Any addition should be recorded on the delivery ticket. A slump taken afterwards describes the concrete as altered rather than as supplied, so tell the technician at the time and the record will show what actually went into the works.

Cubes need a level, secure place to stand where they are protected from sun, frost, vibration and site traffic, and covered so they cannot dry out. Most sites use a thermostatically controlled curing tank, though an insulated box can work on smaller pours where a steady temperature is achievable. The cubes stay in their moulds for an initial period, usually overnight, before being demoulded and moved to controlled curing in water at 20 ± 2 °C until their test age.

Each specimen is given a unique reference that ties it to the sample it came from, the delivery ticket and the part of the structure it represents. We record the date and time of sampling, the mix reference, the ticket number, the pour location and the required test ages, and those references stay with the cubes through curing, testing and the report. If your pour records use their own element numbering, send us the format and we'll follow it.