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?
Mortar Flow
1. Class 1 Mortar Flow (25% Cement Reduction)
It should be noted that no superplasticizer was added to the mortars. The addition of the superplasticizer would make the mix highly flowable and while performing the mini-slump test, the fresh mortar would spread beyond the circumference of the flow table of the mini-slump apparatus.
The following observations were made:
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The control achieved the highest flow spread, indicating that a certain amount of superplasticizer is required to achieve a certain flow for the limestone-cement blends.
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The different grades of fillers used could have affected the packing densities of the resulting mixtures which in turn influenced the flow spreads of the mortars.
2. Class 2 Mortar Flow (50% Cement Reduction)
At a higher replacement level, the following observations were made:
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The control achieved the highest flow spread, indicating that a certain amount of superplasticizer is required to achieve a certain flow for the limestone-cement blends.
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There was a possible effect on the particle packing densities on the resulting mixtures when the limestone fillers were added, thus leading to the variations in the flow spreads.
Concluding Remarks
The limestone fillers do have an effect on the flow properties of the mortars. The different grades of fillers affect the particle packing density of the mix which in turn influences the flow properties.