The impact of original aggregate and attached mortar types …
Recycled concrete aggregate (RA) is composed of original aggregate and attached mortar, both of which are essential in determining the durability and mechanical characteristics of recycled concrete. In this investigation, the sulfuric acid resistance of geopolymer concrete (GPC) was assessed using various RA types, incorporating …
The Anhydrite Process for Sulfuric Acid and Cement
In the process as originally designed, a dry ground rawmix was made comprising anhydrite (or gypsum), shale and/or ash, sand and coke. ... "Production of Cement and Sulphuric …
Resistance of the composite cementitious system of ordinary …
The sulfuric acid resistance of the composite cementitious system of ordinary Portland cement (OPC)/calcium sulfoaluminate (CSA) cement is presented in this paper. Specimens were exposed to sulfuric acid solution for 70 days, and deterioration was evaluated in terms of visual appearance, mass change, and compressive strength …
Buildings | Free Full-Text | Experimental Investigation on the …
The corrosion of alkaline concrete materials exposed to a sulfuric acid environment is becoming more and more prevalent, and its damage assessment is becoming more and more imperative. This study aims to describe the corroded surfaces of concrete with different strength grades (C30, C50, C80) in sulfuric acid environments …
Process for recovering sulphuric acid from …
C04B7/04 — Portland cement using raw materials containing gypsum, ... Method for preparing sulfuric acid by reducing and decomposing gypsum with pyrite CN111118280A (en) * : : ... Public …
Resistance of the composite cementitious system of ordinary …
The sulfuric acid resistance of the composite cementitious system of ordinary Portland cement (OPC)/calcium sulfoaluminate (CSA) cement is presented in this paper.
Semi-batch crystallization of gypsum from calcite and sulfuric acid
Gypsum, the most important raw material of plaster's industry, is a rather interesting example from this point of view as world's known resources are estimated at 2.34 billion tons, which roughly ...
Co-preparation of calcium sulfoaluminate cement and sulfuric acid …
Industrial by-product gypsum is a waste by-product containing mostly calcium sulfate. Problems related to its storage and utilization have become a bottleneck restricting the development of various industries. The authors investigated the feasibility of co-producing calcium sulfoaluminate cement and sulfuric acid through the mass utilization of …
Study of magnesium hydroxide protective coating against …
An accelerated sulfuric acid spraying test in a custom-made spraying ... the formation of gypsum (i.e., the main corrosion product of concrete) during the performed tests, by X-ray Diffraction ...
Frontiers | Performance of high-belite calcium sulfoaluminate cement …
In addition, when the concrete made using ordinary Portland cement (OPC) is exposed to a sulfuric acid environment, the dissolution of CH occurs followed by the formation of gypsum (CaSO 4 ·2H 2 O). This process introduces further damage due to sulfate attack, i.e., expansion due to ettringite formation and subsequent cracking, as …
Role of Gypsum in Cement and its Effects – …
Effects of Gypsum on Cement. Gypsum prevents Flash Setting of cement during manufacturing. It retards the setting time of cement. Allows a longer working time for mixing, transporting and placing. When water is mixed …
Sulfuric Acid Attack on Ordinary Portland Cement and
The deleterious mechanism of acid attack is the dissolution of calcium hydroxide (a hydration product of cement paste) and the formation of gypsum (Ca 2 SO 4 .2H 2 O) and ettringite (Ca 6 Al 2 (SO ...
SULFURIC ACID RESISTANCE OF STRAIN HARDENING …
be related to weight gain of sulfuric acid-exposed cement concrete in early exposure periods, which has been reported in many other studies. Chang et al. suggested that such weight gain could be attributed to many factors, including continuous cement hydration, formation of gypsum due to acid attack, and increase in absorbed water of specimens [20]
The impact of original aggregate and attached mortar types …
1. Introduction. Microbial-induced concrete corrosion (MICC) is a major peril to underground structures, precipitating material degradation and curtailing the lifespan …
SVXP
which is made of sulfuric acid modified steel slag, β-hemihydrate gypsum and calcium aluminate cement. With this, the hydration rate of anhydrite-Ⅱ phosphogypsum is clearly increased and setting time shortened. The performance of self leveling mortar prepared is as per JC/T 1023-2021, with softening coefficient of 0.8. 1. …
Co-preparation of calcium sulfoaluminate cement and …
A life cycle assessment also showed that the co-production of calcium sulfoaluminate cement and sulfuric acid using the decomposition of industrial by …
How to Acid Wash Concrete
Acid etching concrete is an option but not a requirement for epoxying a concrete surface. If you plan to epoxy your garage floor, for example, it does need to be thoroughly cleaned and free of contaminants, and the pores need to be opened. Acid etching is just one way to do this, but it's not the only way.
Study on Concrete Properties under Acid Attacks
II. GENERAL FEATURES OF SULFURIC ACID ATTACK Sulfuric acid [H2 (SO4)] attack on concrete may be characterized by a chemical reaction between the acidic media and cement hydration products and, if soluble, the aggregate particles, results in excessive formation of gypsum (Fig. 2.1). The nature of attack of sulfuric acid on concrete is …
Influence of polymer addition on biogenic sulfuric acid attack of concrete
A simple and reproducible microbiological simulation procedure in combination with a chemical procedure was used to test concrete for its potential resistance towards biogenic sulfuric acid.Concerning fundamental aspects of the corrosion reaction, it was shown that particularly the penetration of H 2 S inside the concrete …
Belitic Calcium Sulfoaluminate Cement Subjected to Sulfate …
Adjustments made to the sulfuric acid solution could have . ... formation of gypsum, and compressive strength, as well as the relationship among the formation of ettringite, pore structure, and ...
(PDF) Effect of Temperature and Acidity of …
Effect of Temperature and Acidity of Sulfuric Acid on Concrete Properties ... As the gypsum material is 65 eroded, the concrete loses its binder and begins to spall, exposing new surfaces. ... Sulphuric acid baths 4 143 …
Chemical, microbiological, and in situ test methods for …
Biogenic sulfuric acid corrosion is often a problem in sewer environment: it can lead to a fast degradation of the concrete structures. Since the involvement of bacteria in the corrosion process was discovered, considerable microbiological research has been devoted to the understanding of the corrosive process.
PRODUCTION OF SULFUR FROM GYPSUM AS AN …
Gypsum (CaSO4. 2H2O) is produced by increasingly more industrial processes, for instance, when calcium carbonate or lime is used to neutralize sulfuric acid containing effluents or when apatite (Ca3(PO4)2. CaF2. CaCO3), the raw material used in phosphoric acid manufacture, is attacked by sulfuric acid.
Gypsum Concrete
Sustainability of gypsum products as a construction material. N. Lushnikova, L. Dvorkin, in Sustainability of Construction Materials (Second Edition), 2016 25.2.2 Gypsum …
Effect of magnesium sulphate and sulphuric acid attack on …
In laboratory, the cement prepared using clinkers: ground calcined clay: low grades of limestone: gypsum in proportion as 50:30:15:5. This cement contains 53-grade OPC, which meets IS 12269–2013 [17].An X-ray fluorescence test was used to find out the material oxide constituents shown in Table 1.The specific gravity of prepared cement …
Biogenic sulfuric acid corrosion resistance of new artificial reef concrete
The biogenic sulfuric acid corrosion simulation device is schematically shown in Fig. 1, which has been modified based on the one reported in literature [18].H 2 S is produced in part 1 while part 2 conducts the biogenic sulfuric acid corrosion. H 2 S was produced by Na 2 S (0.086 M) and HCl (0.042 M). Volumetric flow of Na 2 S and HCl …
Co-preparation of calcium sulfoaluminate cement and sulfuric acid …
DOI: 10.1016/j.jclepro.2020.121801 Corpus ID: 219064874; Co-preparation of calcium sulfoaluminate cement and sulfuric acid through mass utilization of industrial by-product gypsum
Severe Sulfuric Acid Attack on Self-Compacting Concrete …
In this method, the concrete prims are immersed in sulfuric acid solution at a constant pH of 2. During the first weeks, a high precipitation of gypsum occurs on the …
Method of producing sulfuric acid and hydraulic cement from gypsum
The cement clinker made from limestone carries from 0.10 percent to 2 percent S03 according to the fuel and raw materials used in making. ... Process for directly producing sulfur xide and sulfuric acid using gypsum as raw material US8623319B2 (en) * : : Xiaolin Yin ...
Preparation and characterization of Portland cement clinker …
The experimental raw material was fly ash from Shuozhou Second Power Plant of China, and the composition of fly ash was analyzed by XRF spectral qualitative analysis combined with chemical total analysis, the result was shown in table 1.The main chemical composition in fly ash were SiO 2, Al 2 O 3, Fe 2 O 3 and CaO. The physical …