قائمة الطعام
Significant environmental damage can result from the use of natural resources such as cement, aggregate, and water in concrete production. Thus, more sustainable alternatives for concrete production are needed to protect the environment and natural resources. In this study, lightweight pervious concrete production involving recycled …
Type 1 RA can be associated to a RCA: it contains at least 90 % of concrete and natural aggregates, not more than 10 % of clinker, non-pored bricks, sand-lime bricks, less than 2 % of other mineral materials and less than 1 % of asphalt. Foreign substances such as glass, metal slag, etc. should be less than 0.2 %.
MATERIALS USED. The materials used are PPC cement of grade 43, River sand of size passin g through 4.75 mm. IS sieve and retaining o n 150 micron IS sieve, natural coarse aggregate & recycled ...
History. Recycled concrete aggregates or Crushed concrete aggregates has been in use since the ancient times, only to be integrated with gravel, sand, and cement to ensure durability. The practice was first recorded in the 1860s. US construction companies were reluctant to use the technique at first since crushing cured concrete …
The recycled aggregate is an alternative with great potential to replace the conventional concrete alongside with other benefits such as minimising the usage of natural resources in exploitation to produce new conventional concrete. Eventually, this will lead to reducing the construction waste, carbon footprints and energy consumption. This paper aims to study …
Guidelines for Recycled Aggregate Concrete Materials and Structures. Abstract At present, many countries and regions worldwide have already for-mulated recycled …
1. Introduction. For concrete structures, lack of durability might cause serious detrimental damages [1], [2].The permeability of concrete is normally considered as the most important parameter affecting concrete durability [3].It is generally governed by the permeability of concrete constituents, including hydrated cement paste, aggregates, …
1. Introduction. To obtain good quality concrete using recycled aggregate it is necessary to follow the minimum requirements defined by the BCSJ [1], RILEM [2], DIN 4226.100 [3], and prEN 13242:2002 [4].Acceptable properties of aggregates are an elemental base for concrete quality, however adequate mix proportions and concrete …
Recently the use of recycled aggregates in structural concrete has been included in the European standard. EN 206:2013+A1. "Concrete – Specification, performance, production and conformity" (CEN, 2016) only concerns the use of coarse recycled aggregates; their use is restricted to less severe environments.Table 1 shows …
The properties of the recycled aggregate and of the new concrete made from it, with nearly of aggregate replacement, were tested.Significant differences were observed between the properties ...
This study assessed the environmental impacts (EI)s of recycled aggregate concrete (RAC) and natural aggregate concrete (NAC) for structural applications through life-cycle assessments (LCA). The environmental influence of cement content, aggregate production, transportation, and waste landfilling was analysed using the LCA framework …
Recycling concrete provides sustainability several different ways. The simple act of recycling the concrete reduces the amount of material that must be landfilled. The concrete itself becomes aggregate and any embedded metals can be removed and recycled as well. As space for landfills … See more
In developing countries, construction and demolition waste (CDW) is disposed to landfill, causing social, environmental, and economic crises. In these nations, CDW exponentially increase due to their rapid economic growth, industrialization, and urbanization. This paper aims to examine the possibility of recycling concrete waste for …
As such, the recycled or waste materials from damaged structures can be used to replace coarse and fine aggregate, such as recycled asphalt pavement aggregate (RAP), recycled concrete aggregate (RCA), coal waste, silica fume, granulated blast furnace slag, and crumb rubber [9,10,11,12,13,14,15].
Dec 2019. Shubham Kumar. Ritesh Bharti. Prakeern Gupta. Sofi A. PDF | To obtain good quality concrete using recycled aggregate it is necessary to follow the …
1. Introduction. Concrete is known as one of the most highly consumed construction materials. The primary ingredients of a concrete mixture are cement, aggregates (coarse and fine), water and admixtures (Mindess et al., 2003; National Ready Mixed Concrete Association (NRMCA), 2012).Among the aforementioned components, …
Construction and demolition activities consume large amounts of natural resources, generating 4.5 bi tons of solid waste/year, called construction and demolition waste (C&DW) and other wastes, such as ceramic, polyethylene terephthalate (PET), glass, and slag. Furthermore, around 32 bi tons of natural aggregate (NA) are extracted …
This paper reports the results of a study conducted to investigate the effect of Recycled Concrete Aggregate (RCA) replacement with Normal Concrete Aggregate (NCA) at 0%, 50% and . The effect ...
When the w/c ratio is the same the compression strength of concrete made with of recycled aggregate is lower than that on conventional concrete. For the recycled aggregate concrete it will be necessary to add more cement in concrete made with of recycled aggregate in order to achieve the same workability and compression …
This study provides a comprehensive review on recycled aggregate (RA) and recycled aggregate concrete (RAC) regarding their history, recycling, reuse and …
In the present investigation, an attempt was made to study the influence of the strength of parent concrete on the properties of recycled aggregates and recycled aggregate concrete. In this study, four grades of normal concrete mixes: M20, M25, M30, and M40 were considered as parent concrete to produce the recycled coarse …
This includes its use in the construction industry, and more particularly in concrete, which uses large quantities of aggregate. A novel aggregate (RPA) comprising recycled plastic was developed. The aggregate produced was lightweight, with a density ranging from 510 to 750k kg/m3750k kg/m3 and absorption of from 2.7 to 9.81%.
Yuan et al. [18] used machine learning methods such as gradient boosting and random forest (RF) to predict the compressive strength and flexural strength of recycled aggregate concrete. The ...
The use of recycled aggregate concrete (RAC) is considered to be an effective measure to develop green ecological concrete and achieve sustainable development in the construction industry. As a result, RAC has attracted increasing interest in both academia and industry. A number of studies have been conducted on RAC …
This study aims to arrive at models to correlate the mechanical properties of recycled aggregate concrete (RAC). An experiment was performed on the recycled coarse aggregate (RCA) ratio of 0%, 25%, 50%, and with 400kg/m 3 of cement content, varying water-to-cement ratio (w/c) 0.3, 0.4, 0.48, and super plasticizer (SP) …
4.2.1.3 Influence of Strength of Parent Concrete. The strength of parent concrete, the size of natural aggregates used in the parent concrete, and the crushing stages intensely affect the properties of recycled aggregates (Akbarnezhad et al. 2013).The amount of adhered mortar on recycled aggregate and hence the water …
certainly at least 50 kg/m 3 lower than the one used in the concrete with recycled aggregates. The mixing composition (per cubic meter of concrete) was as follows: • 450 kg of cement; • 730 kg ...
Recycled concrete aggregates (RCA) are used in existing green building composites to promote the environmental preservation of natural coarse aggregates (NCA). Besides, the use of RCA leads to ...
The LCA tool utilised in this study is a modified version of that developed by Gursel (2014) and was implemented using Microsoft Excel. The conventional concrete components of the model were validated using the data contained Gursel (2014) before allowing for the inclusion of recycled aggregate, changes in functional unit (to allow for …
It is widely reported that recycled aggregate concrete (RAC) with recycled aggregates demonstrates 17–30% reduction in the compressive strength (Kou …
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