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27 0 obj is required. effect of aggregate shape to the hardened concrete properties. excluding the pores, and bulk specific gravity (BSG), sometimes called Most natural sands and gravel from riverbeds or seashores are smooth and aggregate modulus and concrete coefficient of thermal expansion (CTE) to aggregate CTE, weak correlations were generally obtained between a single aggregate characteristic and concrete performance properties. Hence the mix is cohesive and avoids segregation.Surface texture of aggregates itself depends on rock hardness, grain size, porosity, previous exposure and affects workability, paste demand, initial strength of concrete. 8 0 obj

If the gravel is clean, and well washed the changes of the poor bond is considerably reduced. The compressive strength of concrete depends on the water to cement ratio, degree of compaction, ratio of cement to aggregate, bond between mortar and aggregate, and grading, shape, strength and size of the aggregate (Roccoand Elices, 2009; Elices and Rocco, 2008). George Wainaina <> <> A smooth surface can improve workability yet a rougher surface generates a stronger bond between the paste and the aggregate creating a higher strength.The grading or size distribution of aggregate is an important characteristic because it determines the paste requirement for workable concrete. ���� JFIF �� C These different properties The effect of aggregate shape on concrete strength. space that must be filled and the total surface area that must be covered. 6 0 obj <> apparent specific gravity, includes the volume of the pores. of mixture proportioning, it is important to know the space occupied by It is therefore desirable to minimize the amount requirements. more than hardened concrete.
<> Concrete is more workable when smooth and rounded aggregate is used instead of rough angular or elongated aggregate.Crushed stone produces much more angular and elongated aggregate, which have a higher surface to volume ratio better bond characteristics but require more cement paste to produce a workable mixture.The surface texture of the aggregate can be either smooth or rough.

The particles of well-graded aggregate can be densely packed in concrete, and hence the voids between them decrease. endobj 80 percent of the volume and 70 to 85 percent of the weight of concrete. The shape and texture of the aggregate affects the properties of fresh concrete more than hardened concrete. This factor is of secondary importance.
For this purpose, eight simple cement-based composites were designed, manufactured and tested, with two purposes: to provide experimental data that can throw some light on this involved problem and help in the design of future cement-based composites, and … [ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 600 600 270 368 339 769 541 778 810 175 382 382 500 833 271 329 271 278 541 541 541 541 541 541 541 541 541 541 282 282 833 833 833 412 986 713 678 701 752 625 579 725 793 348 431 743 602 917 774 799 623 799 660 532 671 819 694 995 738 655 609 382 278 382 1000 500 500 491 462 405 491 410 292 461 493 273 248 456 255 765 521 468 488 468 359 356 308 528 498 757 442 470 391 500 500 500 833 600 541 600 271 541 463 1000 500 500 500 1150 532 273 1044 600 609 600 600 271 271 463 463 590 500 1000 500 822 356 273 719 600 391 655 541 368 541 541 541 541 500 500 500 822 400 428 833 329 822 500 329 833 357 357 500 578 500 271 500 357 361 428 848 848 849 412 713 713 713 713 713 713 986 701 625 625 625 625 348 348 348 348 762 774 799 799 799 799 799 833 799 819 819 819 819 655 637 484 491 491 491 491 491 491 686 405 410 410 410 410 273 273 273 273 468 521 468 468 468 468 468 833 468 528 528 528 528 470 472 470] Q. %PDF-1.5 Two nominal mixes, that is, 1:2:4 and 1:3:6 were used in the study. include shape and texture, size gradation, moisture contenThe shape and texture of aggregate affects the properties of fresh concrete Stay informed - subscribe to our newsletter. <> <> Strength of concrete is also affected by the properties of coarse aggregates besides water-cement ratio and other properties. 2 0 obj <>