Apr 3, Normal, Heavyweight, and Mass Concrete (ACI ). Reported by volume ; water-cement ratio; water-cementitious ratio; workability. ACI Committee Appendix 4-Heavyweight concrete mix proportioning. Appendix. in ACI Adjustments to concrete mixture proportions or sources require resubmittal to the design professional as detailed in ACI Formats: Printed Document, PDF, ePub, or site Standard Practice for Selecting Proportions for Normal, Heavyweight, and Mass Concrete ( Reapproved ). 4, Among all available methods, the ACI , the British Road Note Number 4 , and the British DoE [14, 15] methods of mix design are the.
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2-ACI Standard Practice for Selecting Proportions for Normal, Heavyweight, and Mass ConcreteProcedure for Mix Design. S. Hassiotis (Last updated. acteristics of a concrete mixture is called mix design. . Table , ACI , ACI , and Hover . Adapted from Table , ACI and Hover. Jul 19, American Concrete Institute Method of Mix Design (ACI ) 3. unit volume of concrete as per ACI Maximum size of aggregate Bulk.
Estimation of mixing water and air content. The quantity of water per unit volume of concrete required to produce a given slump is dependent on: the nominal maximum size, particle shape, and grading of the aggregates; the concrete temperature; the amount of entrained air; and the use of chemical admixures.
Table 6. Depending on aggregate texture and shape, mixing water requirements may vary above or below those shown in the table.
Before you can use Tabel 6. Usually, if the concrete is exposed to freeze-thaw, as is the case of concrete placed in foundations, you will need air-entrainment. For our example, for a slump of 3 inches and a maximum aggregate size of 1 inch, use the air-entrained part of the table to find that you will need lbs of water per cubic yard of concrete.
The fine print under the table specifies that the water should be reduced by 25 lbs if you are using well rounded aggregates.
Therefore, in this example we will use lbs of water. STEP 4. Selection of Water-Cement or Water-cementitious materials ratio.
Design of Normal Concrete Mixtures Using Workability-Dispersion-Cohesion Method
In absence of such data, Table 6. The strength shown in the tables is for test specimens cured for 28 days in laboratory conditions. Calculation of cement content. Estimation of coarse aggregate content. The volume of coarse aggregate for one cubic yard of concrete is given in Table 6.
Fully analytical methods are less expensive and less time consuming but they have the disadvantage of being less precise because of the variations in the materials characteristics of the aggregates and cements.
Fully experimental or semiexperimental i. Statistical methods also require a certain amount of experimental works but they have an additional advantage in a sense that the expected properties responses can be characterized by an uncertainty variability.
This has important implications for specifications and for production of the cost-effective concrete mixture [ 10 ]. In the present work, an effort has been made to exhibit the application of a statistical approach proposed to obtain optimum proportioning of concrete mixtures using the data obtained through an experiment design considering water-cementitious materials ratio, cementitious materials content, and fine aggregate to total aggregate ratio as design factors.
The experimental data were analyzed statistically and mathematical polynomials regression was developed for concrete strength as a function of mixture variables.
The utility of the developed compressive strength model in optimizing the mixture designs was illustrated considering different possible options. Proposed Approach The proposed approach to optimizing the proportions of concrete mixtures is based on the planned experimental works within the domain of required characteristic performance of concrete and statistical analysis of the data generated, which would reduce the number of trial batches needed.
The proposed approach consists of the following steps. Specification of the Characteristic Performance of Concrete The information pertaining to required workability, strength, and exposure conditions for durability requirements should be first collected.
The workability requirements depend on the mode of transportation, handling, and placing and also on type of construction [ 25 ]. The strength is specified based on the structural requirements for concrete protected from exposure to freezing and thawing and application of deicing chemicals or aggressive substances.
However, for aggressive exposure conditions, the strength specified by the structural designer should not be less than the minimum design compressive strength recommended for the given exposure condition. For example, ACI [ 26 ] has specified minimum design compressive strengths of 28, 31, and 35 MPa, respectively, for concrete exposed to water, freezing-thawing, and chlorides.
The maximum level of cementitious materials content should be selected considering the risk of shrinkage. For example, Soudki et al.
A Statistical Approach to Optimizing Concrete Mixture Design
Experimental Work for Generating Data to Obtain Statistical Model for Optimization An experimental work should be conducted involving designing, preparing, and testing various trial mixtures according to the full factorial experiment design considering the various possible combinations of the levels of the mixture variables within their selected ranges of variation.
The workability of each trial mixture should be equal to or more than the specified value. In case if superplasticizer is needed to achieve the intended workability, the cost of superplasticizer should be added to the cost of cement.
The primary aim of the research is to investigate the effects of varying dosage replacement of cement by animal bone powder ABP in the normal concrete production.
The bone samples collected from Seka Waste Disposal Site of Jimma town, approximately 10km from the bus station where a quantity of waste animal bones can be found. After cleaning and drying, the bone samples burned in the Furnace. The burnt bone was allowed to cool before grinding in a hammer mill and sieving.
The laboratory test results indicated the chemical analyses of bone powder composed similar compounds of oxide in cement but slightly lesser in content based on ASTM C Likewise, the effects of replacing animal bone on the properties of cement such as consistency and setting time remained within the acceptable limits of the Standard Specifications. On the other hand, the results of compressive, flexural tensile, and the split tensile strengths significantly declined from the control specimen during the dosage increment of the replacement made.
Keywords: animal bone powder cement concrete strengths optimum dosage partial replacement 1. Introduction Concrete is a mixture of two components: aggregates and paste. The paste, comprised of Portland cement and water, binds the aggregates usually sand and gravel or crushed stone into a rocklike mass as the paste hardens because of the chemical reaction of the cement and water. Supplementary cementitious materials and chemical admixtures may also be included in the adhesive 1.
Concrete is made to possess different properties by adjusting the proportions and varying the properties of the concrete making materials.
Cement being the main constituent of concrete, its properties affect the properties of concrete the most it is well recognized that cement plays an essential role in concrete 2. The two primary construction materials, sand and aggregates fine and coarse aggregates which are supposed to be cheap because of their availability, are capital intensive both on download and transportation 3.
Today's annual global cement production has reached 2. In the last five years, the growth rate was approximately The production of cement involves the consumption of large quantities of raw materials, energy, and heat. An output from the cement industry is directly related to the state of the construction business in general and therefore tracks the overall economic situation closely.The bone samples collected from Seka Waste Disposal Site of Jimma town, approximately 10km from the bus station where a quantity of waste animal bones can be found.
Many attempts have been made to develop a reliable method for normal concrete mix design in various parts of the world ever since usage of concrete began as a structural material [ 1 — 12 ]. It causes severe disposal problem and continues to accumulate at rising rates, which if not adequately managed, the bone will create increasing environmental issues.
The sustainable development for construction involves the use of nonconventional and innovative materials, and recycling of waste materials to compensate the lack of natural resources and to find alternative ways conserving the environment.
However, it was seen that they employed very long curing cycles from 16 h to 20 h , which makes the resulting concrete energy intensive, rather than energy efficient.
CONCRETE MIX-DESIGN ACI
Concrete is made to possess different properties by adjusting the proportions and varying the properties of the concrete making materials. The maximum level of cementitious materials content should be selected considering the risk of shrinkage. Selection of Water-Cement or Water-cementitious materials ratio. The figure is a reproduction of the plot provided by the DoE method using the ratio instead of the ratio. According to Murdock and Brook [ 19 ], Neville [ 14 ], and El-Rayyes [ 10 ], two of the most necessary and vital conditions to attain economy in the mix design process are the use of locally available materials and the adoption of less restrictive specification requirements.