Influence of Limestone Fillers on the Properties of Concrete
Can cement in concrete be reduced without having any adverse effects on the properties of concrete?
Experimental Works
To be able to achieve the aims of the research, experimental works were undertaken. Different combinations of limestone fillers and cement proportions were used to prepare cement pastes, mortars and concrete mixes.
Key phases of concrete:
1. Cement Paste: Cement + Limestone Filler + Water + Superplasticizer*
2. Mortar: Cement + Limestone Filler + Water + Superplasticizer* + Fine aggregates
3. Concrete: Cement + Limestone Filler + Water + Superplasticizer* + Fine & Coarse aggregates
*A superplasticizer is a chemical which when added to a mix, a lower water content may be used to achieve the same workability.
Tests undertaken
1. Marsh Cone Test
Marsh cone tests were performed on the cement pastes to determine the saturated superplasticizer dosage of each paste.
Variable parameters:
1. Different particle sizes of limestone fillers,
2. Different combinations of cement and the limestone fines,
3. Superplasticizer dosage.
2. Mini-slump Test
Mini-slump tests were performed on the mortars to determine their flow spreads.
Variable parameters:
1. Different particle sizes of limestone fillers,
2. Different combinations of cement and the limestone fines.
3. Concrete Slump Test
Concrete slump tests were performed on the fresh concrete mixes to check if the required workability for each mix was achieved.
Variable parameters:
1. Different particle sizes of limestone fillers,
2. Different combinations of cement and the limestone fines,
3. Superplasticizer dosage.
4. Concrete Compressive Strength Test
The compressive strength of each of the different cubes obtained from the different mixes were tested after 7 and 28 days of water curing.
Variable parameters:
1. Different particle sizes of limestone fillers,
2. Different combinations of cement and the limestone fines.