Rigid Pavement Mix Design
An introduction to laboratory procedures for mix design of rigid pavements, including mix proportioning and testing.
PCC consists of three basic ingredients: aggregate, water and portland cement. According to the Portland Cement Association (PCA, 1988): “The objective in designing concrete mixtures is to determine the most economical and practical combination of readily available materials to produce a concrete that will satisfy the performance requirements under particular conditions of use.” PCC mix … Read more
When aggregate, water and portland cement paste are combined to produce a homogenous substance, that substance takes on new physical properties that are related to but not identical to the physical properties of its components. Thus, several common mechanical laboratory tests are used to characterize the basic mixture and predict mixture properties. Unlike HMA, it … Read more
Admixtures are the ingredients in PCC other than aggregate, portland cement and water. Typically, an admixture is added to alter a specific PCC property such as workability, setting time, strength or durability. Type Desired Effect Material Accelerators Accelerate setting and early strength development Calcium chloride, triethanolamine, sodium thiocyanate, calcium formate, calcium nitrite, calcium nitrate … Read more
A concrete mix is to be designed for use in a 250 mm (10 inch) thick JPCP pavement. The desired properties are: Slump = 25 mm (1.0 inch) Average 28-day flexural strength of at least 4.5 MPa (650 psi) Coarse aggregate: nominal maximum size = 37.5 mm (1.5 inch), dry-rodded weight = 1600 kg/m3 (100 … Read more
The American Concrete Institute (ACI) mix design method is but one of many basic concrete mix design methods available today. This section summarizes the ACI absolute volume method because it is widely accepted in the U.S. and continually updated by the ACI. Keep in mind that this summary and most methods designated as “mix design” … Read more