ACI 211.4R-93 Guide for Selecting Proportions for High-Strength Concrete with Portland Cement and Fly Ash

This guide gives a typically applicable method for deciding on mixture proportions for high-strength concrete and optimizing these combination proportions on the basis of trial batches. ACI 211.4R-93 Guide for Selecting Proportions for High-Strength Concrete with Portland Cement and Fly Ash. The approach is constrained to excessive strength concrete produced the use of traditional materials and manufacturing techniques.
Recommendations and tables are based totally on contemporary practice and information provided by contractors, concrete suppliers, and engineers who have been involved in tasks dealing with high-strength concrete.

ACI 211.4R-93 Guide for Selecting Proportions for High-Strength Concrete with Portland Cement and Fly Ash

ACI 211.4R-93 Guide for Selecting Proportions for High-Strength Concrete with Portland Cement and Fly Ash

Mixture proportioning procedure

Completion of the following steps will end result in a set of adjusted high-strength concrete laboratory trial proportions.
These proportions will then furnish the foundation for field trying out concrete batches from which the optimum
mixture proportions can also be chosen.
1. Step 1-Select stoop and required concrete strength -Recommended values for concrete slump are given in  following Table. Although high-strength concrete with HRWR has been produced effectively besides a measurable initial slump, an preliminary beginning stoop of 1 to 2 in. prior to adding HRWR is recommended. This will insure an sufficient amount of water for mixing and enable the superplasticizer to be effective.

For high-strength concretes made except HRWR, a recommended slump vary of 2 to 4 in. may additionally be chosen according to the kind of work to be done. A minimum value of 2 in. of hunch is advocated for concrete without HRWR. Concretes with less than 2 in. of slump are tough to consolidate due to the excessive coarse aggregate and cementitious materials content. 
The required concrete electricity to use in the trial mixture process must be determined the use of the guidelines supplied in Chapter 2.

2.  Step 2-Select most measurement of aggregate-Based on power requirements, the recommended maximum sixes for coarse aggregates are given in Table 4.3.2. ACI
318 states the most size of an aggregate have to not exceed one-fifth of the narrowest dimension between sides of forms, one-third of the depth of slabs, nor three-quarters of the minimum clear spacing between individual reinforcing bars, bundles of bars, or prestressing tendons or ducts.
3. Step 3-Select most reliable coarse aggregate content -The most advantageous content material of the coarse combination depends
on its strength potential traits and maximum size. The advocated superior coarse aggregate contents, expressed as a fraction of the dry-rodded unit weight
(DRUW), are given in Table 4.3.3 as a function of nominal maximum size. 
Once the most efficient coarse mixture content has been chosen from Table 4.3.3, the oven-dry (OD) weight of the coarse combination per yd3 of concrete can be calculated
using Eq. (4-1)

 

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