Mortar strength prediction equations

For the purpose of developing the equations for the compressive strength prediction for latex-modified mortars and concretes, all-inclusive consideration of various factors such as polymer-cement ratio, water-cement ratio, and air content is required. Expanding Talbot s void theoryP on ordinary cement mortar and concrete, OhamaP P l defined binder-void ratio (a) or void-binder ratio (P), and empirically proposed the equations using a and p to predict the compressive strength of the latex-modified mortars and concretes as follows ... 

Using a somewhat different approach, Knbfel (1989) reliably predicted the 28-day mortar strength with a simple formula containing microscopically determined percentages of alite, belite, aluminate, and ferrite. The equation is F28 = 3(alite) + 2(belite) + aluminate - ferrite. F28 is termed the characteristic strength. The equation is designed for use within a cement plant where production conditions over the period of investigation are virtually identical. 

Variations in predicted 28-day mortar strength among cement producers led Moir (1997) to study the burnabilities of kiln feeds from 15 cement plants in the laboratory, using a horizontal programmable tube furnace. An equation to calculate the temperature required for 1% free lime was given as ... 

Similar studies have been carried out by Cook who came to the conclusion that ballistic mortar is not a reliable method for determining field strength of HE s. Nevertheless, the maximum available work (A) in the mortar can be predicted quite accurately by the use of equation 11.8 given on p 268-L of Ref 17 and equation 11,12 given on p 273-R of Ref 17 [See also Detonation (and Explosion), Impetus and Available Energy in ]... 

Ono presented the following multilinear regressive equation (among several other similar equations), which gives a prediction of 28-day mortar-cube strength ... 

A multiregressional equation predicting the 28-day mortar cube strength was presented by Rao, Akhouri, and Sinha (1992), the data coming from rotary and vertical shaft kiln clinkers. The prediction has a standard deviation of 17.9 kg/cm, utilizing alite and belite percentages and average crystal sizes. 

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