Durability, sustainability and cost analysis of the effect of SNF superplasticizers on locally produced concrete in Ghana

Using conventional methods of concrete production to achieve expected results is challenging, hence the use of chemical admixtures which is also little researched in Ghana. The study conducted a concrete mix design for project construction, following significant challenges encountered in attaining the desired strength of 30MPa at a slump of S3 (100-150mm). To address the challenge, a concrete mix design was produced according to EN 206 standard mix design at the laboratory of the Council for Scientific and Industrial Research (CSIR)-Building and Road Research Institute (BRRI)-Ghana. A chemical admixture consisting of high-range water-lowering sulfonated naphthalene formaldehyde (SNF) was used in the design. Once the laboratory mix design was completed, the concrete mix proportions were adopted for field application. When employing 385kg/m3 of Portland cement, a water-to-cement ratio of 0.49, a water content of roughly 189kg/m3, and an admixture content of 3.28kg/m3, the laboratory mix design yielded a 28-day compressive strength of 37 MPa (5366 psi). After 28 days of curing, both the laboratory (37MPa) and field-prepared (31MPa) concretes met the minimum strength of 30MPa with the laboratory-controlled concrete exhibiting compressive strength results that were approximately 16% greater than those of the field-prepared concretes. The report revealed that the use of SNF resulted in 18% savings in cement thereby reducing carbon emissions and 5% savings in cost, urging a case for the use of chemical admixtures for structural and non-structural concrete components of the project for the sake of durability, sustainability and cost.