The influence of aggregate gradation on the fresh and hardened concrete properties

Abstract

This experimental study is focused on the aggregate gradation impact on the properties of fresh and hardened concrete. For the experiment, 9 mix design were prepared with the constant content of cement, effective water, plasticizer and aggregate. The variable factor is represented by different proportions of 4 fraction (0/0.7, 0/4, 4/8, 8/16). Consistency by slump and flow table in time, compressive strength, water absorption and density were measured. Some significant differences were observed. Consistency by the slump test varied from 0 to 170 mm after 5 minutes and from 0 to 50 mm after 30 minutes of concrete mixing. Consistency by flow table varied from 340 to 530 mm after 5 minutes and 320 to 460 mm after 30 minutes. Standard compressive strength varied from 50.8 to 61.6 MPa. Water absorption varied between 4.7 and 5.9 mass % and density from 2380 to 2440 kg.m−3.

Concept of Evaluation of Mineral Additives’ Effect on Cement Pastes’ Durability and Environmental Suitability

“…Excluding samples NZ7.5_0.3 and NZ7.5_0.4, oven-dried samples achieved significant higher values (increase from 10.5 rel.% up to 48.9 rel.%) of compressive strength on day 28 day, as those in ssd state. This has been proven in our previous studies [ 21 , 104 ].…”

“…With increase in cement paste amount of same w/c, the volume of the pores increases, thus increasing porosity and permeability [ 19 ]. The main factor of cement paste quantity is the aggregate (mainly its granularity and grain shape) [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. This is due to voids that are created between grains that have to be fulfilled by cement paste.…”

Optimizing manufactured sand content in mortars and its influence on fresh and hardened state

“…In this regard, manufactured sand is a byproduct of the coarse aggregate production that has been successfully used for making concrete. Although it has been concluded that angular shape of fine aggregates increases compressive strength in comparison with rounded shapes [2][3][4], the detrimental impact on fresh properties is the main limiting factor to increase its use. However, increasing the content of manufactured sand in new concrete involves environmental benefits since lower quantities of natural sand would be required.…”