Prediction of Concrete Mix Cost Using Modified Regression Theory

The cost of concrete production which largely depends on the cost of the constituent materials, affects the overall cost of construction. In this paper, a model based on modified regression theory is formulated to optimise concrete mix cost (in Naira). Using the model, one can predict the cost per cubic meter of concrete if the mix ratios are given. The model can also give possible mix ratios for a specified cost. Statistical tool was used to verify the adequacy of this model. The concrete cost analysis is based on the current market prices of concrete constituent materials. A Price Fluctuation Factor (PFF) can be used to take care of price fluctuations over time

PREDICTION OF FLEXURAL STRENGTH OF CHIKOKO POZZOLANA BLENDED CEMENT CONCRETE USING OSADEBE’S REGRESSION FUNCTION

Chikoko mud is abundant in the mangrove swamps of the Niger Delta area of Nigeria. Its utilization in concrete production is traceable to its pozzolanic properties. In this paper, a regression model is developed to predict and optimize the flexural strength of chikoko pozzolana blended cement concrete using Osadebe’s regression function. The results obtained from the derived regression model are very close to those obtained from experiment. The model was tested for adequacy using a Fisher test at 5% level of significance and was found to be adequate. A computer program coded in basic language was used to select the mix ratios that would optimize the flexural strength of chikoko pozzolana blended cement concrete. The computer program is user-friendly and can be used to select the mix ratios corresponding to a desired strength value with reasonable accuracy and without waste of time. http://dx.doi.org/10.4314/njt.v36i3.

Split tensile strength of soilcrete blocks

With the ever increasing problems associated with dredging of rivers to obtain river sand, reduced dependence on river sand should be encouraged by using alternative materials in block production. This work deals with the production of soilcrete blocks using readily available and affordable laterite. Split tensile strength of the blocks was determined. A model for predicting the split tensile strength was formulated using Scheffe’s simplex lattice design. The mathematical model passed the adequacy tests.Keywords: Soilcrete blocks, Split tensile strength, model, Scheffe’s simplex lattic