Innovative Gypsum Particle Composite Used as Building …
Wood particles, water, gypsum, and retarder are mechanically mixed and then pressed at room temperature to form a gypsum– particle composite (GP) using a semidry manufacturing technology
(PDF) Effect of Using Sugar and Gypsum as a Retarder on …
gypsum content up to 3%, for higher value of gypsum the strength starts to decrease, this is for both 0.4 and 0.5 W/C ratio, and it may b e attrib uted to the effect of setting time
Deterioration Reason and Improvement Measure of the
The retarding effect of protein retarder on phosphorus building gypsum (PBG) and desulfurization building gypsum (DBG) was investigated, and the results show that protein retarder for DBG can effectively prolong the setting time and displays a better retarding effect, but for PBG shows a poor retarding effect. Furthermore, the …
Dual role of gypsum: Set retarder and strength …
One of the most important uses of natural gypsum is the manufacture of ordinary Portland cement (OPC), which is included in amounts of 2.5-5%, acting as an OPC setting time retarder [42, 43]. If ...
What is the purpose of adding gypsum in cement?
Gypsum is a mineral and is hydrated calcium sulfate in chemical form. Gypsum plays a very important role in controlling the rate of hardening of the cement. During the cement manufacturing process, upon the cooling of clinker, a small amount of gypsum is introduced during the final grinding process. Gypsum is added to control the...
The experimental study of flue gas desulphurization gypsum …
Abstract: Instead of natural gypsum with FGD gypsum as cement retarder, study the affection of different gypsum content on the properties of ordinary Portland cement. The results showed that gypsum can replace natural gypsum as cement retarder. There is larger surface area and setting time, and appropriate content in the gypsum …
Preparation and Hardening Performance of Lightweight …
Desulfurized building gypsum (DBG) has great application potential and can be used to produce lightweight plastering gypsum (LPG). In this work, DBG was …
Study on Gypsum Plasters with Modified Waste Mycelium as Retarder
Advance Researches in Civil Engineering. Effect of Mixing Rate of Plaster with Water on Properties of Gypsum Plaster. ... Common gypsum retarders include organic citric acid, sodium polyphosphate and protein based materials. Compared with sodium citrate and sodium polyphosphate, protein based materials can effectively prolong the setting time ...
Comparing the effects of a retarder and accelerator on properties …
Comparison of physical and mechanical properties of civil construction plaster and recycled waste gypsum from São Paulo, Brazil. J. Build. ... Developing highly efficient gypsum retarders is of great significance for improving gypsum retardation technology. ... Journal of Industrial and Engineering Chemistry, Volume 33, 2016, pp. …
207) The most commonly used retarder in cement is
Engineering; Civil; Civil Set-1; Structural Engineering I; 207. Structural Engineering I MCQ with Answers; 207) The most commonly used retarder in cement is gypsum. calcium chloride. calcium carbonate. none of the above. Answer is: gypsum. Structural Engineering I MCQ with Answers
What are various functions of retarders in Concrete? What …
Ex: Gypsum, Starch, Sugar etc. Increase strength by decreasing W/C ratio. Gypsum is the retarding agent in cement to prevent it from premature hardening. The addition of gypsum in cement not only influences its setting time but other properties as well. Gypsum is fire resistant.
Mechanism, Types and Effects on Properties
Retarders for concrete are used to delay the initial setting time of the concrete upto an hour. They are generally used in the hot weather condition to counter the rapid …
Gypsum Retarder | MIKEM CHEMICAL
Gypsum Retarder MIKEM Gypsum Retarder Description MIKEM gypsum retarder is a high-performance and environmentally friendly protein-based retarder that can slow down the setting time of gypsum plaster. Even applied with small amounts, our high-efficiency gypsum retarder produces excellent retardation effects with minimal loss of gypsum …
Study on retarding feature and retardation mechanism of …
Gypsum retarding material has developed into a big family comprised of organic acid retarder, alkaline phosphate retarder and protein retarder, and each …
Study on retarding feature and retardation mechanism of …
Extremely rapid setting time of building gypsum severely limits its further processing and application. Gypsum retardation is an indispensable technology that provides a long period of plasticity for gypsum construction. Developing highly efficient gypsum retarders is of great significance for improving gypsum retardation …
Partial Cement Replacement in Concrete with Gypsum …
Chandara C, Azizli KAM, Ahmad ZA, Sakai E (2009) Use of waste gypsum to replace natural gypsum as set retarders in Portland cement. Waste manag 29(5):1675–1679 ... Department of Civil Engineering, University of British Columbia, Vancouver, BC, Canada. Clark Lim . Rights and permissions. Reprints and permissions.
What is Concrete Retarder – Types, Uses, Advantages and …
Concrete retarders, also known as retarding admixtures, play a crucial role in construction by slowing down the setting process of cement-based mixtures. Let's delve into the …
Gypsum is added in the manufacture of Portland cement in …
Gypsum is added in the manufacture of Portland cement in order to:Lengthen the setting time of cementExplanation:When gypsum is added to Portland cement, it acts as a retarder, which means it slows down the setting time of the cement. This is important because it gives the workers enough time to work with the cement before it becomes rigid.
What Is a Concrete Surface Retarder
Retarders for use on forms or concrete surfaces are likely to be made up of such substances as sugars, dextrins, hydroxylated carboxylic acids or their salts, or lignosulfonates, the same classes of materials used in retarding admixtures. Concrete Surface Deactivator. Surface Deactivator creates a polymeric flim that acts as a water …
Preparation and Hardening Performance of Lightweight Gypsum …
Desulfurized building gypsum (DBG) has great application potential and can be used to produce lightweight plastering gypsum (LPG). In this work, DBG was modified by adding different proportions of sawdust, retarder, and hydroxypropyl methylcellulose (HPMC) water-retaining agent to prepare LPG. When the sawdust content is greater …
Effect of Competitive Adsorption between Polycarboxylate
Preferential addition of PCE can effectively reduce this negative effect, whereas the preferential addition of HPMC has a positive effect on enhancing the viscosity of gypsum slurry. These results can provide useful guidance for the preparation of high-fluidity gypsum paste in practical engineering.
Effects of several retarders on setting time and strength of …
The effects of eight retarders, including tartaric acid, sodium tartrate, salicylic acid, melamine, sucrose, white cement, sodium triphosphate, and citric acid, on …
The Effects of Combined Retarders on the Properties of …
Citric acid, sodium gluconate, and sodium tripolyphosphate were used to design and prepare a desulfurized gypsum paste containing single or combined …
Comparing the effects of a retarder and accelerator on …
Gypsum (CaSO 4 ·2H 2 O) as a widely used building material needs to have good mechanical strength and low water absorption. This paper investigated the effect …
Gypsum as a Construction Material- A Review of Recent …
The engineering and physical properties especially the rigidity of the gypsum are mostly affected by the microstructure of the gypsum pastes after it is hardened. The Le chatellier's law clearly explains the mechanism of setting of ... the effect of water-gypsum ratio, the addition of retarders or accelerators, the added sand/lime paste.
Sugar in Concrete | Effect of Sugar on Concrete Strength
IS Code for Civil Engineer [Q&a] IS 456 Most Important Point Part- 1; IS 516:1959 Most Important Point (Method of Tests For Strength of Concrete) ... Retarders and Accelerators are required to increase and diminish the initial setting time of concrete respectively. e.g. Retarder– sugar and gypsum etc. & Accelerator- salt (cacl2) etc.
How Many Types Of Chemical Admixture Used For Concrete
Gypsum is the most widely used as a Retarder in concrete. Usually, 2 to 3% gypsum is added in concrete which fulfills the all purposes. ... Is the main problem of civil engineering. There are numerous materials and methods available for waterproofing in …
Effect of the Adsorbing Behavior of Phosphate Retarders on …
Phosphate is usually considered as an excellent retarder in cement-based materials. It is often thought that the mechanism behind this excellent retarding effect is attributed to the precipitation of calcium-based phosphate or the formation of a complex on the surface of the cement particles.
Effect of different ways of STPP retarder addition on
A new civil engineering material: normal temperature modified phosphogypsum embedded filler ... Use of Waste Gypsum to Replace Natural Gypsum as Set Retarders in Portland Cement[J]. Waste Manage., 2009, 29(5): 1675–1679. Article Google Scholar ... College of Material Science and Engineering, Chongqing University, …
Modification of phosphogypsum using circulating fluidized …
DOI: 10.1016/j.conbuildmat.2022.127630 Corpus ID: 248445855; Modification of phosphogypsum using circulating fluidized bed fly ash and carbide slag for use as cement retarder @article{Li2022ModificationOP, title={Modification of phosphogypsum using circulating fluidized bed fly ash and carbide slag for use as cement retarder}, …