Shear-bond behavior of self-compacting geopolymer concrete to conventional concrete

2022 ◽  
Vol 321 ◽  
pp. 126167
Author(s):  
Purwanto ◽  
Januarti Jaya Ekaputri ◽  
Nuroji ◽  
Bobby Rio Indriyantho ◽  
Aylie Han ◽  
...  
2021 ◽  
Vol 11 (15) ◽  
pp. 6740
Author(s):  
Rana Muhammad Waqas ◽  
Faheem Butt

Geopolymer concrete, also known as an earth-friendly concrete, has been under continuous study due to its environmental benefits and a sustainable alternative to conventional concrete construction. The supplies of many source materials, such as fly ash (FA) or slag (SG), to produce geopolymer concrete (GPC) may be limited; however, quarry rock dust (QRD) wastes (limestone, dolomite, or silica powders) formed by crushing rocks appear virtually endless. Although significant experimental research has been carried out on GPC, with a major focus on the mix design development, rheological, durability, and mechanical properties of the GPC mixes; still the information available on the structural behavior of GPC is rather limited. This has implications in extending GPC application from a laboratory-based technology to an at-site product. This study investigates the structural behavior of quarry-rock-dust-incorporated fiber-reinforced GPC columns under concentric and eccentric loading. In this study, a total of 20 columns with 200 mm square cross-section and 1000 mm height were tested. The FA and SG were used as source materials to produce GPC mixtures. The QRD was incorporated as a partial replacement (20%) of SG. The conventional concrete (CC) columns were prepared as the reference specimens. The effect of incorporating quarry rock dust as a replacement of SG, steel fibers, and loading conditions (concentric and eccentric loading) on the structural behavior of GPC columns were studied. The test results revealed that quarry rock dust is an adequate material that can be used as a source material in GPC to manufacture structural concrete members with satisfactory performance. The general performance of the GPC columns incorporating QRD (20%) is observed to be similar to that of GPC columns (without QRD) and CC columns. The addition of steel fibers considerably improves the loading capacity, ductility, and axial load–displacement behavior of the tested columns. The load capacities of fiber-reinforced GPC columns were about 5–7% greater in comparison to the CC columns. The spalling of concrete cover at failure was detected in all plain GPC columns, whereas the failure mode of all fiber-reinforced GPC columns is characterized with surface cracking leading to disintegration of concrete cover.


2021 ◽  
Author(s):  
Aamer Abbas ◽  
◽  
Yaqoob Yaqoob ◽  
Ola Hussein ◽  
Ibrahim Al-Ani ◽  
...  

This study presents experimentally the bond behavior of light-weight concrete specimens with grouted reinforcing bars in comparison with conventional concrete specimens. A total of (9) pull-out specimens were studied; (3) specimens of conventional concrete, (3) specimens of light-weight concrete, and other (3) specimens of grouted light-weight concrete. Two variables are adopted in this investigation: specimen width and type of concrete (conventional concrete, light-weight concrete and grouted light-weight concrete). The study contains a discussion of the general behavior of the specimens in addition to the study of the ultimate bond capacity, maximum bond stresses and the relationship between the stress and the slip for different pull-out specimens. Results show that bond strength is highest for the largest specimen size (bond strength of grouted light-weight concrete specimen with specimen width 400 mm is higher than that of the specimen with (200 mm) width by about (13.13%)). Also, bond strength is highest for the grouted light-weight concrete specimen (bond strength of grouted light-weight concrete specimen is higher than conventional concrete specimen by (11.11%)).


Author(s):  
Abhinay I. Deshmukh

The Bubble Deck technology developed in Europe makes use of high-density polyethylene hollow spheres to replace the ineffective concrete in the centre of the slab, thus decreasing the dead weight and increasing the efficiency of the floor. Concrete is good in compression and hence is more useful in the compression region than in the tension region. The reduction in concrete can be done by replacing the tension zone concrete. Keeping the same idea in mind, an attempt has been made to find out the effectiveness of plastic bubbles by replacing concrete in the tension zone of Ordinary Portland Cement Concrete (OPCC) and Geopolymer Concrete (GPC) beam. Geopolymer Concrete does not form calcium- silicate-hydrates (CSHs) for matrix formation and strength like OPCC but utilizes the polycondensation of silica and alumina precursors to attain structural strength. In this project, M25 concrete mix is used to prepare both OPCC and GPC beams. The trial mix is tested for compressive strength. Flexure test is done is done for 28 days of curing of the beams. This paper presents the results of the experimental investigations carried out to determine and to compare the flexural behaviour of geopolymer concrete (GPC) beams with conventional concrete beams of same grade. The beams were tested under two point monotonic loading. Performance aspects such as load carrying capacity, first crack load, ultimate load, load-deflection behaviour, moment-curvature behaviour, crack width, crack spacing and the modes of failure of both types of beams were studied. The test results showed that the geopolymer concrete exhibits better performance compared to conventional concrete of same grade.


2019 ◽  
Vol 8 (4) ◽  
pp. 12142-12146

Geopolymer concrete is one of the major developments in recent years resulting in utilization of fly ash in huge quantities and eventually reducing cement consumption and ultimately reducing emission of greenhouse gases.The geopolymer concrete is produced by using activated fly ash as binder material instead of cement. Geopolymer concrete accomplishes great strength and looks similar to conventional concrete. Recycled coarse aggregate (RCA )which is coming from demolition of construction of old and existing structures has been used in this study. The durability property; acid attack resistance with partial replacement of coarse aggregate by recycled aggregate in geopolymer and conventional concrete for the different composition such as 10, 20, 30 and 40percentage for a period of 15, 45,75 and 105 days has been evaluated. From the results it was observed that in both natural and recycled aggregate of Geopolymer concrete is highly resistant to acids such as sulphuric acid and hydrochloric acid compared to conventional concrete of respective aggregates.


2019 ◽  
Vol 2 (2) ◽  
pp. 65
Author(s):  
Purwanto P. ◽  
Himawan Indarto

Portland cement production process which is the conventional concrete constituent materials always has an impact on producing carbon dioxide (CO2) which will damage the environment. To maintain the continuity of development, while maintaining the environment, Portland cement substitution can be made with more environmentally friendly materials, namely fly ash. The substitution of fly ash material in concrete is known as geopolymer concrete. Fly ash is one of the industrial waste materials that can be used as geopolymer material. Fly ash is mineral residue in fine grains produced from coal combustion which is mashed at power plant power plant [15]. Many cement factories have used fly ash as mixture in cement, namely Portland Pozzolan Cement. Because fly ash contains SiO2, Al2O3, P2O3, and Fe2O3 which are quite high, so fly ash is considered capable of replacing cement completely.This study aims to obtain geopolymer concrete which has the best workability so that it is easy to work on (Workable Geopolymer Concrete / Self Compacting Geopolymer Concrete) and obtain the basic characteristics of geopolymer concrete material in the form of good workability and compressive strength. In this study, geopolymer concrete is composed of coarse aggregate, fine aggregate, fly ash type F, and activators in the form of NaOH and Na2SiO3 Be52. In making geopolymer concrete, additional ingredients such as superplastizer are added to increase the workability of geopolymer concrete. From this research, the results of concrete compressive strength above fc' 25 MPa and horizontal slump values reached 60 to 80 centimeters.


2020 ◽  
Vol 184 ◽  
pp. 01092
Author(s):  
M Niveditha ◽  
Srikanth Koniki

Geopolymer concrete is prepared by reacting silicate as well as aluminate consisting materials with a caustic activator. More often, waste materials such as GGBS, fly ash, slag from metal and iron production are used. Recent investigations adding new materials like Alccofine, which improves the properties of geopolymer concrete even at ambient temperature condition. This research paper presents a details literature survey on the durability properties of geopolymer concrete. Various research literatures are previewed on durability of geopolymer concrete with the addition of different supplementary cementious materials as their necessity is increasing due to insistent constituents. Past studies from the literature reviews suggested that replacement of cement with chemical and mineral admixtures enhanced the properties of strength and durability of concrete. The micro structures, Morphological structures by SEM, lower shrinkage, higher mechanical strengths, superior durability with environmental sustainability are observed. XRD studies shown enhanced polymerisation reaction which is responsible for development of strength. Elevated temperatures and Surface deterioration are controlled in GPC than OPC. Geopolymer concrete provides better resistance for specimens to chemical attack and also water absorption, sorptivity, porosity have good influence to the durability properties in ambient curing conditions compared to conventional concrete.


2020 ◽  
Vol 32 (7) ◽  
pp. 04020167
Author(s):  
Rakesh Paswan ◽  
Md. Reyazur Rahman ◽  
S. K. Singh ◽  
B. Singh

2020 ◽  
Vol 184 ◽  
pp. 01095
Author(s):  
T Srinivas. ◽  
G Abhignya. ◽  
N.V Ramana Rao.

In present day scenario, concrete construction is rapidly increasing for different uses and aspects irrespective of the economy and its usage. Due to this imbalanced usage of economy, scarcity of raw materials increasing day by day and environment is getting affected due to manufacturing of cement. This study has been done how to reduce environmental pollution by using different kind of bi product materials in replacement to conventional concrete, which is made up of OPC. The cement can be replaced with fly ash; GGBS, rice husk ash etc, aggregates are being partially replaced with recycled aggregates which come from demolished structures and alkaline liquids such as sodium silicates and sodium hydroxide can be used in concrete, which is called geopolymer concrete. Literature review has been carried out to find the optimum content of aggregates to be replaced and the flexure behavior of the beams is being evaluated. From the literature study, it has been identified that the optimum compressive strength is achieved at 30% replacement of recycled aggregate and ductility natures of both Geopolymer and conventional concrete beams are almost similar.


2018 ◽  
Vol 159 ◽  
pp. 01017 ◽  
Author(s):  
Nuroji ◽  
Daniel Herdian Primadyas ◽  
Ilham Nurhuda ◽  
Muslikh

This paper describes the research on bond behavior of plain reinforcing bars in geopolymer and normal concrete. The geopolymer concrete in this research was made of class F fly ash taken from Tanjung Jati Electric Steam Power Plant (PLTU) with Sodium Hydroxide (NaOH) and Sodium Silicate (Na2SiO3) as alkaline activator, added in the mixture. The effect of bar size was studied by varying the bar diameter in range 10 mm to 19 mm. Each bar was casted in the center of concrete blocks made of geopolymer as well as normal concrete. Pull-out tests were carried out to the specimens that have reached 28 days of age. The test results show that the bond behavior of geopolymer concrete differs substantially from normal concrete, where geopolymer concrete has a higher bond strength when compared to normal concrete with identical concrete strengths.


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