Compression strength of concrete and mortar prepared by vacuum carbon-reinforced aggregate is observed to be 13.6% and 30% higher than ordinary recycled concrete, respectively. Also, the proposed ...
In concrete, an interfacial transition zone (ITZ) is defined as the region located between the cement paste and coarse aggregate, which normally has a higher porosity than the bulk hydrated paste. This distinct region is widely accepted as the weakest link in concrete, and controls the mechanical and durability performance of the concrete …
Using concrete slurry waste and waste brick masonry powder to produce artificial aggregates using the disc granulation method.. Long CSW sedimentation time had a negative effect on the pelletizing efficiency and properties of the artificial aggregates.. The artificial aggregate particles sequestered approximately 3% of CO 2 under CO 2 curing, …
Crushing the demolished waste concrete as aggregate to prepare fresh concrete may cause aggregate internal damage leading to strength reduction. To counter this issue, in the current study, the recycled aggregate is mixed with nano-calcium oxide in a vacuum reactor, and then a high concentration of carbon dioxide is introduced to fill the …
For the preparation of aggregates, in general, waste concrete elements are mechanically broken into small-sized pieces. The small pieces are further crushed …
For the island-reef engineering construction background in the South China Sea, the research studied the preparation technology, mechanical properties and chloride ion diffusion behavior of coral aggregate seawater concrete and discussed the steel bars corrosion behavior of coral aggregate seawater concrete (CASC) and reliability analysis …
Gomes and Brito (2009) found that concrete with 50% WCB as coarse aggregates slightly increased the carbonation and chloride ion penetration compared with normal aggregate concrete. Pacheco-Torgal and Jalali (2010) reported that the chloride ion penetration of concrete was decreased when WCB fully replace natural coarse or …
Steel slag, Portland cement, and fly ash were used as the raw materials for preparing the artificial aggregates. The steel slag was firstly ground into powders with a specific surface area of 260 m 2 /kg, and then mixed with Portland cement and fly ash following the mix proportions shown in Table 2.Three batches of mix were designed as …
After the preparation, FCS-HSCA with a continuous gradation was used as aggregate to prepare concrete. Fig. 9 displays the mechanical properties of concrete prepared with different aggregates. The replacement of FCS-HSCA for FCS results in an increase in compressive strength from 59.9 MPa to 66.1 MPa, while there is an increase …
Cement and silica fume were used as binding materials and their ratios (Silica fume: Cement = 1:5) were kept constant in all the samples. This ratio of cement and silica fume was chosen because studies show that 30% silica fume addition resulted in decrease of workability, so 20% is preferred [22], [27]. The water/binder (w/b) weight …
High carbon emissions, shortages of natural aggregates and environmental pollution of waste concrete powder (WCP) have become open issues for the traditional concrete industry. Aggregates prepared by crushing and screening waste concrete usually possess poor mechanical properties. Meanwhile, the WCP cannot be effectively …
SS is pre-treated by wet carbonation, and then mixed with cement to prepare the paste sample (the amount of steel slag in the paste sample varies from 0 to 60% at intervals of 10%); mixed with cement and standard sand to prepare mortal sample (the steel slag content in the mortar sample is 10%). The flow chart is shown in Fig. 3. …
Five mixtures of LWAC were prepared with various water-binder ratio (0.2, 0.3, 0.4) and volume ratio of fine aggregate (0.35, 0.4, 0.45). The mix proportions are shown in Table 3.Due to the fact that the high water absorption of WCB could affect the workability of fresh concrete, the aggregates were treated by pre-wetting method.
Arbitrary Method of Proportioning Concrete. The general expression for the proportions of cement, sand and coarse aggregate is 1 : n : 2n by volume. 1 : 1 : 2 and 1 : 1.2 : 2.4 for very high strength. 1 : 1.5 : 3 and 1 : 2 : 4 for normal works. 1 : 3 : 6 and 1 : 4 : 8 for foundations and mass concrete works.
f. Curing of concrete a. Selection and preparation of ingredients: Various ingredients such as cement, sand, aggregate, and water should be carefully selected according to the desired purpose and strength of concrete. b. Mixing of ingredients: Ingredients of PCC are adequately mixed with their relative proportion. Mixing may be of …
Li et al. [30] prepared HDCC incorporating recycled fine concrete aggregate (RFCA) with compressive strength of 40 MPa and strain capacity of more than 0.8%. ... Pre-absorption of water in the preparation of brick aggregates increases the actual water content of the system, which to some extent hinders the geopolymerization and loosens …
Exposed aggregate concrete is a kind of functional concrete material with excellent sound absorption and noise reduction function [19], [20]. Based on different interface properties and aggregates strength, its surface strength could achieve about 19–70 MPa. Meanwhile, the abrasion resistance of exposed aggregate concrete is …
In addition, unlike the sintered lightweight aggregate concrete, ... and Bayer red mud was developed and utilized for both binders and the preparation of artificial aggregates. An all-solid waste concrete strategy was achieved by gradually replacing cement and natural rock aggregates in cement concrete. Several conclusions were …
The reuse of construction and demolition waste has become vitally important because of the requirements of environmental protection and sustainable development. The vibration mixing process is a new technology and novel method that improves the performance of concrete by optimizing the mixing process without changing …
Abstract: This chapter describes and provides data on relevant technological, economic and environmental aspects of operating construction and demolition waste …
For ordinary aggregate concrete, the failure of concrete is initiated from separation of the interface between the mortar and aggregate surface (mainly due to tension and shear), …
A review on the use of plastic waste in preparation of cement mortar and concrete preparation is already available [22]. ... Considering the intricate relationship between mixture proportion and properties of plastic aggregate concrete, a random forest (RF) model, a machine learning algorithm, is employed to predict compressive strength …
Preparation of concrete2.2.1. Cement and sand. The cement used in this study complied with the provisions of GB 175-2020 "General Portland Cement" [37]. It was composed of clinker, gypsum, and volcanic ash admixture, belonging to P.O 42.5 ordinary Portland cement. ... As shown in Fig. 18, the compressive strength of RCP artificial …
Chapter 4-Construction procedure. 4.1 -General considerations. 4.2-Preparation of concrete. 4.3-Grout inserts, sounding. 4.4-Forms (high-density) concrete4.5-Coarse. …
Recycling of concrete aggregates obtained from C&D waste towards concrete production is a vital strategy to tackle the environmental impact of both C&D waste and concrete production ... For the preparation of the mixes, sand, coarse aggregate and cement (dry ingredients) were blended for 3 min. Effective water amount …
In several studies, fine natural aggregate of cement mortar and concrete was replaced by coarse sized aggregate too [2,13]. Table 1 highlights the types and amounts of substitution of natural aggregate by plastic …
In this paper, tunnel granite muck was processed into low carbon, coarse and fine aggregates, and low carbon aggregates were used to prepare bridge concrete. Meanwhile, the mechanical properties, anti-permeability, and frost resistance of concrete were investigated. The results demonstrated that the concrete prepared using low …
Preparation of Recycled and Multi-Recycled Coarse Aggregates Concrete with the Vibration Mixing Process. by. Fa Yang. 1, Yunshi Yao. 1,2,*, Xinxin Wang. 1, Jin Wei. 1 and. Zhongxu Feng. 1,2.
For example, with an adequate mix of cement and aggregates such as sand and gravel, a material can be created that enables the absorption of water and, at the same time, …
The water-cement ratio for such concrete is 0.5-0.4 with cement sand ratio 1: 2 and if the coarse aggregate is also added then 1:1:2.and aluminum content should be 0.05%- 0.08% of the concrete mass. 3) For light weight aggregate …
The prepared aggregates possessed a resistivity in the range of 3.40–7.34 Ω·m due to the efficient conductive network in the aggregate established by carbon fibers and carbon black. However, the influence of the prepared conductive aggregates on the conductivity of cement-based materials was not investigated the above mentioned studies.
1. Introduction. Concrete the most broadly used construction material (Prabhu et al., 2014), aggregate makes 70% of its volume is the principal component material in concrete production and consumes globally 8–12 million tons of natural aggregate annually (Devi and Gnanavel, 2014, Al-Jabri et al., 2009).The aggregate classifications used are …
Aggregates. Aggregates are inert granular materials such as sand, gravel, or crushed stone that, along with water and portland cement, are an essential ingredient in …
Recycled aggregate concrete (RAC), prepared by its partial or full replacement, has been studied to show that the properties are influenced by the properties of the RA themselves [[17], [18]]. As the RA particle size increases, the total number of cracks in the RCAC rises more prominently compared to the cracks in the NAC [19]. The …
CHAPTER 1—INTRODUCTION. Hydraulic cement concrete is a cement and water paste in which aggregate particles are embedded. Aggregate is granular material such as sand, gravel, crushed stone, blast-furnace slag, and lightweight aggregates that usually …
3.5 Analyze the mechanical of artificial aggregate concrete. The artificial aggregate was replaced by 10%, 30%, 50%, 70% and of natural aggregate to prepare concrete. The apparent density surface of nature and artificial aggregate is 2730 kg/ m 3, 2600 kg/m3, and the water absorption of 0.7% and 3.0%. There is a certain gap in the …
Additionally, utilizing urban solid waste for concrete aggregate preparation can reduce carbon emissions. Ban et al. ... The compressive strength of the prepared multi-shell lightweight aggregate concrete ranged from 39.8 to 54.5 MPa, splitting tensile strength from 2.44 to 2.95 MPa, and the carbon emission and cost were 36.2% and …
The optimal mixture of recycled aggregate concrete is obtained as water cement ratio of 0.5, volume ratio of recycled coarse aggregate of 42.0%, replacement of river sand, 0% crushed brick ...