Cloburn Quarry Company Ltd - it's simple & ancient...use natural stone

Concrete Aggregates from Cloburn Quarry

Why Choose and Specify Cloburn Aggregates

Cloburn aggregates are unique and versatile due to the high silica content and associated surface texture. The main attributes of these aggregates are low absorption and porosity and also, high crushing strengths. When Cloburn aggregates are used in concrete, they produce a hardened concrete with the lowest value of drying shrinkage and wetting expansion of any aggregate.

Aggregate	Sand	Shrinkage Value	Wetting Expansion
Natural Aggregate	Natural Sand	0.053%	0.040%
Cloburn Granite	Natural Sand	0.035%	0.035%
Cloburn Granite	Cloburn Granitsand	0.024%	0.022%

As you can see, the effect of using a different sand source with Cloburn aggregates produces the same effect with a slightly higher drying shrinkage and wetting expansion value.
Due to the foregoing, the concrete produced from Cloburn aggregate forms a strong, highly durable and impermeable concrete which affords maximum protection to steel reinforcement and resistance to frost.

Physical Properties of Cloburn to Other Concrete Aggregates

British Standard Test	Cloburn Granite	Typical Granite	Typical Gravel	Typical Whinstone	Typical Limestone	Explanation
10% Fines Value	360 kN	230 kN	180 kN	220 kN	170 kN	Higher Value is Best
A.I.V (Aggregate Impact Value)	10%	21%	22%	14%	24%	Lower Value is Best
A.C.V. (Aggregate Crushing Value)	12%	22%	23%	15%	24%	Lower Value is Best
A.A.V. (Aggregate Abrasion Value)	1.1%	4%	16%	5%	10%	Lower Value is Best
Water Absorption	0.6	1.2	2.0	1.8	1.6	Lower Value is Best
Shape/Flakiness	12	22	25	28	30	Lower Value is Best
Density	2.55	2.69	2.69	2.80	2.66	Lower Value is Best

Because of the cubical shape of our aggregate in conjunction with the low absorption rate, this contributes to a good workability and reduced water cement ratio.

Long Term Durability

Concrete produced from Cloburn Granite and our washed Granitsand promotes a hard wearing surface due to the high silica content, which is resistant to wear and attrition.

Concrete wear and abrasion

Although much information is available on the technical properties of aggregates, very little is known about sand. In fact the only test routinely carried out is a grading analysis. Naturally occurring sand is used predominantly as the fine aggregate in both ready-mixed and pre-cast concrete. In order to prove the advantage of using a sand manufactured from a high-strength granite, a series of tests were carried out in NAMAS approved laboratories..

Test	Natural Sand	Cloburn Granitsand	Improvement
Each sand was crushed in a ball mill and the degree of degeneration or size reduction in a given time was measured.	242%	129%	86%
The physical weight of material lost with a narrow wheel abrasion apparatus on mortar samples was measured.	714g	360g	98%
The resistance to rotational abrasion using Railtrack's Taber Test was measured.	Taber value 410	Taber value 260	58%