Report #2: Reactivity of the clay candidate as Supplementary Cementitious Material

Implementation: Sampling: 4-6 weeks

Description: it includes sampling the clay deposit of interest, through the collection of individual samples and/or composite samples, that can be used to produce a representative sample of the entire deposit, which can also be evaluated.

1. Accompanying the local geology team at sampling during the exploration of the deposit. A minimum area of 100 ha will be studied, to guarantee reserves at least in the order of 1 Mt of clay.

A sampling grid with spacing 250m x 250m will be defined. In each intersection of the axis of the grid individual samples shall be taken, either in trenches or as boreholes. For each individual axis a composite sample shall be prepared through blending of individual samples. Sampling depth will be dictated by the geology of the deposit. A typical study in a 100ha area would produce 25 individual samples, 5 composite samples and 1 integral sample, for a total of 31 samples. The client can change the sampling design for own purposes, at an extra cost.

2. For each of the samples collected the following experimental program shall be undertaken:

.       Chemical and mineralogical composition.

b.      Determining kaolinite content through the combination of thermal analysis and X ray diffraction.

c.       Lab calcination at 800ºC, with quality of calcination controlled using TG.

d.      Assessment of reactivity[1] through:

ü  Evaluation of heat of hydration at 72h in an isothermal calorimeter of a cement paste with composition of LC3-50 (53% CEM I 42,5 N, 30% calcined clay, 15% limestone, 2% gypsum)

ü  Strength at 24h, 7d and 28d in standard mortars with composition of LC3-50 (53% CEM I 42,5 N, 30% calcined clay, 15% limestone, 2% gypsum)

Number of samples covered in this study: 31.

NOTE: further simples can be tested upon request; this implies an extra cost.

Expected results:

Full characterization of the material available at the clay deposit subject of interest, including chemical and mineralogical composition, kaolinite content, potential reactivity as SCM and physic-mechanical properties in LC3-50 systems (50% clinker, 30% calcined clay, 15% limestone, 5% gypsum).