4 2 COARSE AGGREGATES Section defines the acceptable limits for all uses of coarse aggregat Coarse aggregates are divided into classes based on quality requirements as noted in the Classification of Aggregates table Class AP is the highest class and is assigned to aggregates which m eet the requirements for all INDOT usBecause maximum aggregate size can impact concrete properties such as shrinkage and also the cost of concrete the largest aggregate size consistent with the requirements of should be permitted With the w/cm fixed the larger the nominal maximum size of aggregates the lower the cement content for a given consistency Or stated

اکنون پرس و جوAggregates can be classified in many ways Classification of aggregates based on shape and size such as coarse and fine aggregates are discussed here Aggregates are the important constituents of the concrete which give body to the concrete and also reduce shrinkage Aggregates If not stated the 10 limit shall apply C989 Specification for Slag Cement for Use in Concrete and 425 When the order is for coarse aggregate Mortars The grading size number see 101 and Table 3 or C Test Method for Length Change of Concrete Due to alternate grading as agreed between the purchaser and aggre Alkali

اکنون پرس و جوMaximum Size versus Nominal Maximum Size The specification I prepared for a project calls for “Maximum coarse aggregate size to be 1 in nominal” I intended this provision to mean that almost all of the coarse aggregate used in the concrete would pass the 1 in 250 mm sieve and some would be retained on the 3/4 in 190 mm sieve The size of coarse aggregate for concrete 1 2 4 avsaeu size of coarse aggregate for concrete 1 2 4 ASTM C535 12 Standard Test Method for Resistance to 11 This test method covers testing sizes of coarse aggregate larger than 19 mm 3 / 4 in for resistance to

اکنون پرس و جوdifferent proportions of size number 57 coarse aggregate and fine aggregat The CF and 8 18 charts for the WG and NWG combined aggregates are plotted in Fig 1 and 2 respectively Combined aggregate void content was determined according to ASTM C29 except that the combined aggregates were blended thoroughly using a scoop or shovel Fig 3 Jan 24 32 By the CT 382 definition the maximum aggregate size is 3/4 and the nominal maximum aggregate size is 1/2 In the November version of CT 202 nominal maximum aggregate size is defined as one sieve size larger than the first size to retain more than 10 By this definition the nominal maximum aggregate size for the material example

اکنون پرس و جوThe first second and third treatments utilized the coarse aggregate sizes of 10 mm 12 mm and 15 mm control respectively The constituents that were used to formulate the concrete mixes were Portland cement river sand as fines and crush stone as coarse aggregat A constant mix proportion of 1 2 4 and a constant waterGranulated blast furnace slag fine aggregate 21 Steel furnace slag both fine and coarse 32 Gravel Coarse Aggregates There is a specific requirement for gravel coarse aggregates regarding crushed particl This requirement applies however only when gravel

اکنون پرس و جوMar 27 32 The mix 1 2 4 represents the M15 grade of concrete which means the concrete formed with this ratio has compressive strength of 15 kN/m^2 1 2 4 represents the amount of cement fine aggregate sand and coarse aggregate to be added during batchin If there is a deficiency in a locally available fine aggregate concrete may benefit from the addition of air entrainment additional cement or a supplemental cementitious material SCM to address these shortcomings Broad coarse aggregate gradation ranges are listed in Table 2 of ASTM C 33

اکنون پرس و جوseveral factors such as mixing ratio aggregate size texture coarse and fine aggregate compaction method curing period and some parameters have been discussed in literature review The results showed the concrete aggregate size of 20mm has a 457 higher compressive strength than the concrete aggregate size of 10mmMay 04 32 Aggregate materials are generally broken up into two classifications of size fine and coarse aggregate Coarse aggregates are typically sizes larger than the 4 sieve Fine aggregates are typically sizes smaller than the 4 sieve What people refer to as dust is typically aggregate smaller than the 200 sieve Simple enough right Any questions

اکنون پرس و جوValues for sand suitable for concrete should range between 23 and 31 Coarse sand has a higher fineness modulus than fine sand The fineness modulus influences the bulk volume of coarse aggregate Concrete Technology 10 Bulk Volume of Coarse Aggregate Once the MSA and FM of sand are determined these values can be used to determine bulkSIEVE ANALYSIS OF FINE AND COARSE AGGREGATE TXDOT DESIGNATION TEX 401 A CONSTRUCTION DIVISION 3 5 LAST REVIEWED SEPTEMBER 42 Fine Aggregate—Laboratory Method 421 Select a representative sample of approximately 500 g from material that has been thoroughly dried at a temperature of 110 177 5 176 C 230 177 9 176 F

اکنون پرس و جوSECTION 701 AGGREGATES coarse aggregate for concrete Fine Aggregates for Concrete A General Requirements Fine aggregate is natural sand having hard strong durable Sieve Size Grade 1 Grade 2 Grade 3 Grade 4 Grade 5 1 1/2 inch 375 mm 100 1 inch 250 mm 100 TABLE OF CONTENTS CHAPTER 1 Selection of Aggregates coarse and fine aggregate sources and ensuring there is an adequate supply of each Where practical multiple aggregate sources coarse and fine should be used Dry weight of sample after washing g Sieve Size Weight g Retained Percent Retained Percent Passing

اکنون پرس و جوseveral factors such as mixing ratio aggregate size texture coarse and fine aggregate compaction method curing period and some parameters have been discussed in literature review The results showed the concrete aggregate size of 20mm has a 457 higher compressive strength than the concrete aggregate size of 10mmshows these limits for fine aggregate and for one size of coarse aggregate There are several reasons for specifying grading limits and nominal maximum aggregate size they affect relative 82 Design and Control of Concrete Mixtures EB001 Fig 5 4 Range of particle sizes found in aggregate for use in concrete Fig 5 5

اکنون پرس و جوdifferent proportions of size number 57 coarse aggregate and fine aggregat The CF and 8 18 charts for the WG and NWG combined aggregates are plotted in Fig 1 and 2 respectively Combined aggregate void content was determined according to ASTM C29 except that the combined aggregates were blended thoroughly using a scoop or shovel Fig 3 421 Mix one batch of mortar for the fine aggregate test sample and one batch of mortar for the standard sample All batches shall have the same quantity of fine aggregate Mix the batches for the two conditions alternately 422 Mold three 2 inch 50 mm cubes from each batch 423 Test the three cubes for compressive strength at 14 days 5

اکنون پرس و جوEFFECTS OF AGGREGATE SIZES ON THE CONCRETE STRENGTH In the sense that the materials involved in this project were capital intensive more especially cement so in carrying out the work one must have to be careful in the selection and collection of materials to be used in the casting of the concreteJan 15 32 Aggregate serves as a reinforcement to add strength to composite materials such as concrete Aggregates can be categorized into three groups fine aggregate coarse aggregate or all in aggregate Fine aggregate such as concrete or masonry sand is defined as material that mostly passes through a 475 mm IS sieve

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