residential development guide for home extensions and new dwellings 



HANSON BUILDING PRODUCTS - Building Materials and Architectural Building Products

Hanson is one of the world's largest suppliers of heavy building materials to the construction industry. They produce aggregates (crushed rock, sand and gravel), ready-mixed and precast concrete, asphalt and cement-related materials and a range of building products including concrete pipes, concrete pavers, tiles and clay bricks. 

They are part of the HeidelbergCement Group, which employs 53,000 people across five continents. HeidelbergCement is the global leader in aggregates and has leading positions in cement, concrete and heavy building products.

Most home extensions requiring planning permission will probably benefit from using their products during the build.  Many Architects or House Extension Designers can incorporate their products within the scheme design drawings and specifications.

The following article may be of interest for homeowners researching this type of building product for inclusion within their own house extension scheme.

7 Standards For Evaluating the Quality of Aggregate

If you're not in the construction industry, you might think that rocks are rocks. After all, aggregate is simply mined and crushed stone, gravel, and other natural, mineral resources, so how different in quality could one deposit be from another? The fact is, however, that there is a vast difference between different kinds of rocks and types of mineral deposits. Not all rocks make good aggregate, and a potential quarry or pit site is evaluated extensively for the quality of its aggregate before digging, drilling, or blasting take place. So how is the quality of aggregate evaluated? This is a question that impacts not only geologists and quarry owners, but the customers who need to buy quarry for their construction projects. Here are 7 standards for evaluating the quality of aggregate.

Till. Till is the eroded bits of the rock that have accumulated somewhere downstream from a rock deposit and can be studied before quarrying begins. Geologists study till in order to get a picture of the rock it came from. Bigger particles mean higher quality aggregate. Bigger particles also mean that the rock formation the till came from is close by and easier to find and evaluate.

Boulder size. Once the rock formation is discovered, geologists have to determine how big the boulders are. Bigger boulders are cohesive and have fewer cracks in them, and are therefore considered stronger and higher quality aggregate.

Reactive minerals. When tests are done on unmined minerals, geologists check to see if the rock is full of impurities such as reactive minerals, clay, alkaline elements, silicone, or free quartz. If it has a lot of any of these things, it's probably low quality aggregate, and therefore not desirable.

Fracture frequency. The more cracks and fractures there are in rock deposits, the weaker the rock is in general. Of course, it's easier to mine, since it's naturally coming apart, but fracture frequency is an important indicator of the quality of the aggregate.

Shape and surface texture. If the rock breaks apart into angular, sharp pieces, with rough surfaces, that's an indication of high quality aggregate. Rounder, smoother pieces are indicative of weaker rock that crumbles easily, and generally a sign of low quality aggregate.

Hardness and abrasion resistance. To be high quality aggregate, rock has to be very difficult to break. Sure, it makes the quarriers' jobs harder, but it provides aggregate that won't collapse or crumble under the pressure of well-travelled roads or occupied buildings. A rough surface of the stone also makes for higher quality aggregate, since it will resist being shifted by the weight that will be pressed on it.

Resistant to breakdown. This is a measure of how quickly a rock type erodes. If it erodes fairly rapidly when exposed to air, water, or an opposing force, it's low quality aggregate, but if it resist erosion and doesn't break down quickly, then it may be considered high quality aggregate.

These are only some of the standards that geologists, quarry operators, and construction supervisors use to judge the quality of their construction aggregate. There are others, but as you can see, not all aggregate is created equa