Cement Minerals Research Articles

Research on the Properties of Mineral-Cement Emulsion Mixtures Using Recycled Road Pavement Materials.

The reduction in natural resources and aspects of environmental protection necessitate alternative uses of waste materials in the area of construction. Recycling is also observed in road construction where mineral–cement emulsion (MCE) mixtures are applied. The MCE mix is a conglomerate that can be used to make the base layer in road pavement structures. MCE mixes contain reclaimed asphalt from old, degraded road surfaces, aggregate improving the gradation, asphalt emulsion, and cement as a binder. The use of these ingredients, especially cement, can cause shrinkage and cracks in road layers. The article presents selected issues related to the problem of cracking in MCE mixtures. The authors of the study focused on reducing the cracking phenomenon in MCE mixes by using an innovative cement binder with recycled materials. The innovative cement binder based on dusty by-products from cement plants also contributes to the optimization of the recycling process in road surfaces. The research was carried out in the field of stiffness, fatigue life, crack resistance, and shrinkage analysis of mineral–cement emulsion mixes. It was found that it was possible to reduce the stiffness and the cracking in MCE mixes. The use of innovative binders will positively affect the durability of road pavements.

Predicting the time-dependent hydro-thermo-mechanical properties of cement-based materials based on thermodynamic and multi-scale modeling

Studying the performance evolution of cementitious materials is of great significance for a better understanding of the durability and prediction of the service life of the concrete structure. This paper develops a model to predict the time-dependent effective mechanical, transport, and thermal properties of cement-based materials based on the volume partitioning scheme and multi-scale homogenization method. In the volume partitioning scheme, the thermodynamic modeling is coupled with a cement hydration kinetics model and a microstructure model for two types of calcium silicate hydrates (C-S-H) to calculate the time evolution of the volumes of gel pores, capillary pores, hydrates, and residual cement minerals in the hydrated cement system. In the multi-scale model, a simplified representation of the microstructure of cement-based materials is presented. The effective macroscopic properties of cement-based materials are predicted from their microstructure by combining Self-Consistent (SC) and Generalized Self-Consistent (GSC) schemes. Finally, the predictions are compared with experimental data from the literature, showing a good agreement.

Bioaugmentation with Acidithiobacillus species accelerates mineral weathering and formation of secondary mineral cements for hardpan development in sulfidic Pb-Zn tailings

The development of hardpan caps has great potential in rehabilitating sulfidic and metallic tailings, which may be accelerated by using exogenous Acidithiobacillus species. The present study aims to establish a bioaugmentation process with exogenous Acidithiobacillus species for accelerating the weathering of sulfidic minerals and formation of secondary mineral gels as precursors for hardpan structure development in a microcosm experiment. Exogenous Acidithiobacillus thiooxidans (ATCC 19377) and A. ferrooxidans (DSM 14882) were inoculated in a sulfidic Pb-Zn tailing containing negligible indigenous Acidithiobacillus species for accelerating the weathering of pyrite and metal sulfides. Microspectroscopic analysis revealed that the weathering of pyrite and biotite-like minerals was rapidly accelerated by exogenous Acidithiobacillus species, leading to the formation of secondary jarosite-like mineral gels and cemented profile in the tailings. Meanwhile, approximately 28% Zn liberated from Zn-rich minerals undergoing weathering was observed to be re-immobilized by Fe-rich secondary minerals such as jarosite-like mineral. Moreover, Pb-bearing minerals mostly remained undissolved, but approximately 30% Pb was immobilized by secondary Fe-rich minerals. The present findings revealed the critical role of exogenous Acidithiobacillus species in accelerating the precursory process of mineral weathering and secondary mineral formation for hardpan structure development in sulfidic Pb-Zn tailings.

Osteocytes but not osteoblasts directly build mineralized bone structures.

Bone-forming osteoblasts have been a cornerstone of bone biology for more than a century. Most research toward bone biology and bone diseases center on osteoblasts. Overlooked are the 90% of bone cells, called osteocytes. This study aims to test the hypothesis that osteocytes but not osteoblasts directly build mineralized bone structures, and that defects in osteocytes lead to the onset of hypophosphatemia rickets. The hypothesis was tested by developing and modifying multiple imaging techniques, including both in vivo and in vitro models plus two types of hypophosphatemia rickets models (Dmp1-null and Hyp, Phex mutation mice), and Dmp1-Cre induced high level of β-catenin models. Our key findings were that osteocytes (not osteoblasts) build bone similar to the construction of a high-rise building, with a wire mesh frame (i.e., osteocyte dendrites) and cement (mineral matrices secreted from osteocytes), which is a lengthy and slow process whose mineralization direction is from the inside toward the outside. When osteoblasts fail to differentiate into osteocytes but remain highly active in Dmp-1-null or Hyp mice, aberrant and poor bone mineralization occurs, caused by a sharp increase in Wnt-β-catenin signaling. Further, the constitutive expression of β-catenin in osteocytes recaptures a similar osteomalacia phenotype as shown in Dmp1 null or Hyp mice. Thus, we conclude that osteocytes directly build bone, and osteoblasts with a short life span serve as a precursor to osteocytes, which challenges the existing dogma.

Experimental Study on Interface Strength Between Hardened Cement Paste-Aggregate

The interfacial transition zone (ITZ) is a weak part of concrete, which is the main reason that the mechanical properties of concrete are far lower than those of hardened cement paste and aggregate itself. In order to improve the mechanical properties of concrete ITZ, the effects of cement varieties, water-binder ratio, mineral admixtures and aggregate types on the strength of hardened cement paste-aggregate ITZ were studied by orthogonal test. A linear regression model between interfacial bonding splitting tensile strength and splitting tensile strength of hardened cement paste was proposed. The results show that the water-binder ratio has the greatest impact on the mechanical properties of ITZ, followed by aggregate. The interfacial bonding splitting tensile strength of five kinds of aggregate and cement paste is in the order of marble > coral > granite > basalt > quartzite. The optimal interface test combination is as follows: water-binder ratio 0.25, aggregate is marble, P•O52.5 cement, slag content 15%, fly ash content 20% and silica fume content 10%. The optimal cement slurry combination is: water-cement ratio 0.25, basic magnesium sulfate cement, slag content 15%, fly ash content 20% and silica fume content 10%. The linear regression model between interfacial bond splitting tensile strength and hardened cement paste splitting tensile strength is established by dividing aggregate, which is of great significance to study the law of interfacial strength.

Computed tomography-guided microwave ablation combined with percutaneous vertebroplasty for treatment of painful high thoracic vertebral metastases

Purpose To retrospectively evaluate the efficacy and safety of computed tomography (CT)-guided microwave ablation (MWA) combined with percutaneous vertebroplasty (PVP) as a treatment for painful high thoracic vertebral metastases (T1–T4). Materials and Methods In this retrospective study, 23 adult patients (33 high thoracic vertebral metastases) with moderate to severe pain were treated with CT-guided MWA and PVP. The procedural effectiveness was evaluated using a Visual Analog Scale (VAS), daily morphine consumption, and the Oswestry Disability Index (ODI) before and immediately after the procedure and during follow-up. Results Technical success was achieved in all patients. The mean pre-procedure VAS score and morphine doses were 6.7 ± 1.7 (5–10) and 105.2 ± 32.7 (30–150) mg, respectively. The mean VAS scores and daily morphine doses at 24 h and 1, 4, 12, and 24 weeks post-operatively were 3.2 ± 1.4 and 41.3 ± 9.6 mg; 1.8 ± 1.0 and 31.5 ± 12.2 mg; 1.4 ± 1.3 and 19.6 ± 12.4 mg; 1.1 ± 0.8 and 14.5 ± 9.6 mg; and 1.0 ± 0.7 and 13.9 ± 9.3 mg, respectively (all p < 0.001). ODI scores significantly decreased (p < 0.05). Minor cement leakage occurred in 10 patients (30.30%) with no symptoms. Follow-up imaging showed no local tumor progression. Conclusions Preliminary results suggest MWA combined with PVP is an effective and safe treatment for painful high thoracic vertebral metastases (T1–T4) and can significantly relieve pain and improve the quality of life of patients. However, its efficacy should be confirmed by mid- and long-term studies.

EVALUATION OF DYNAMIC QUALITIES OF MOVEMENT OF RE-EQUIPPED HOPPER CARS OF PILS OF LONG-TERM OPERATION

As part of the work, a theoretical and experimental study (based on running dynamic tests) of the running qualities of empty hopper cars, converted from cement trucks and mineral trucks, was conducted. Computer simulation of the dynamics of empty hopper wagons converted from cement and mineral wagons depending on the condition of the track, the technical condition of the wagons and the weight of the container, the repeated presence of maximum vertical deviations and horizontal deviations of the track. A significant disadvantage of the railway transport of Ukraine is the limitation of the speed of trains with individual freight cars in an empty state, which are equipped with carts model 18-100. Among the reasons for the descent of the wheels of cars from the rails are: malfunctions of the running gear of the cars (fracture of the side frames and spring beams of the carts, malfunctions of the roller bearings of the axle box), wear of friction damper elements, unacceptable deviations and upgrades. As part of the work, a theoretical and experimental study (based on running dynamic tests) of the running qualities of empty hopper cars, converted from cement trucks and mineral trucks, was conducted. Computer modeling of the dynamics of empty hopper wagons, converted from cement and mineral wagons depending on the condition of the track, the technical condition of the wagons and the weight of the container and studies of the dependence of the wheel stability on the east.

PERILAKU GESER BALOK BETON BERTULANG MUTU TINGGI DENGAN VARIASI FLY ASH BATU BARA, PASIR POZZOLAN DAN BONGKAHAN CANGKANG SAWIT

The utilization of high strength concrete particularly on construction is an option in structural elements. High Strength Concrete (BMT) is a compressive strength exceeding 6000 psi or 41 MPa. High quality concrete can be obtained by mixing superplasticizers (high range water reducers) and cementitious mineral additives in the form of fly ash, pozzofume (super fly ash), and microscopy (silicafume). In this study, it will used the substitution of cement material using coal fly ash, fly ash pozzolan sand and palm shell ash fly ash, fine aggregates using pozzolan sand, coarse aggregates palm shell. The aim of this study is to compare the shear behavior of normal high quality reinforced concrete beams and beams with the addition of material substitution. The high quality reinforced concrete beam specimens were designed to experience shear failure by strengthening the bending area. Reinforced concrete beam specimens of beam size 150 mm x 300 mm x 2200 mm with shear reinforcement diameter 6 mm (fy) 423.46 MPa, compressive reinforcement 16 mm (fy) 412.39 MPa and tensile reinforcement 19 mm (fy) 462, 24 MPa. The beam specimen is pure flexural tensile strength with a size of 150 mm x 150 mm x 600 mm and a cylindrical specimen with a diameter of 150 mm x 300 mm in height. The magnitude of the flexural tensile strength for BMT-N with f cc = 44.4 MPa is 4.5, and for BMT-FBPP with f cc = 51.04 MPa which is 5.35 with FAS 0.3. The results of the two beams experienced shear failure, with a comparison of laboratory and theoretical shear capacity of 2,292 BMT-N with a maximum load of 27,200 MPa, BMT-FBPP 1,720 with a maximum load of 21,410 MPa. The values of deflection and ductility tend to decrease in BMT-FBPP beams which are equal to 19.780% and 6%.

The Influence of New Silicate Cement Mineral Trioxide Aggregate (MTA Repair HP) on Metalloproteinase MMP-2 and MMP-9 Expression in Cultured THP-1 Macrophages.

The aim of the present study was to investigate the new silicate cement mineral trioxide aggregate (MTA Repair HP) with respect to its effect on the inflammation process involving the tooth and periodontal tissues. The composition of MTA Repair HP was supplemented with plasticizer agents which can have a negative effect on the modulation of tooth inflammation. The silicate-based material in question is widely used in regeneration of the pulp-dentin complex, treatment of perforations of various locations in the tooth, as well as in surgical treatment of the complications of periapical tissue. The improved bioceramic restorative cement can affect the expression of metalloproteinases MMP-2 and MMP-9 in monocytes/macrophages involved in modulation of inflammation and regenerative processes of the tooth and periodontal tissues. The novel aspect of the present study lies in the application of the model of THP-1 monocyte/macrophage and applying the biomaterial in direct contact with the cells. Hence, it provides a representation of clinical conditions with respect to regenerative pulp and periodontal treatment with the use of MTA Repair HP. A lack of macrophage activation (as measured with flow cytometry) was found. Moreover, the study identified a lack of expression stimulation of the studied metalloproteinases (with the use of Western blotting and fluorescent microscopy). Similarly, no increase in MMP-2 and MMP-9 concentration was found (measured by ELISA method) in vitro when incubated with MTA Repair HP. Based on the results it can be concluded that new MTA Repair HP does not increase the inflammatory response in monocytes/macrophages associated with the activity of the described enzymes. It can also be speculated that they do not affect the process of dentin regeneration in which MMP-2 and MMP-9 play significant roles.

Comparison of Long-Term Strength Development of Steel Fiber Shotcrete with Cast Concrete Based on Accelerator Type.

This study analyzed the effect of accelerating agents, such as aluminate, cement mineral, and alkali-free accelerators, on the long-term performance of steel-fiber-reinforced shotcrete. The shotcrete performance was studied based on the type and amount of steel fiber added. Performance tests were performed to identify the accelerator providing better long-term performance to the steel-fiber-reinforced shotcrete. Changes in strength and flexural performance over time were investigated. The compressive strength and flexural strength tests on 1-, 3-, 6-, 12-, and 24-month-old test specimens were performed, wherein 37 kg of steel fiber was added to the cement mineral and aluminate mixes, and 40 kg of steel fiber was added to the alkali-free mix. The 1-month compressive strength result of all the test variables satisfied the Korea Expressway Corporation standard. The compressive strength of the cast concrete and shotcrete specimens increased with age, demonstrating a strength reduction, particularly in the 24-month-old shotcrete specimens. Thus, the shotcrete performance may deteriorate in the long-term. In the 24-month-old specimen, substantial flexural strength reduction was observed, particularly in the aluminate and alkali-free specimens. The relative strength of the specimens was compared with that of the cast concrete mold specimens. The results suggest the use of alkali-free accelerators, considering the long-term performance of tunnels and safety of workers. Moreover, increasing the steel fiber performance rather than the amount of low-performance steel fiber must be considered.

Durability control through design and health monitoring during construction

Durability control through design and health monitoring of a new viaduct (bridge), to achieve an 80-year service life, is discussed. Manufacture of durable concrete is also discussed and deals mainly with the geometry/shape selection of the structural elements and materials selection (especially the adequate cement type and mineral additions to decrease concrete's porosity). Durability health monitoring was performed during the construction stage, based on concrete performance using the saturated electrical resistivity technique, using cores extracted at new fabricated structural elements. Finally, discussion is presented on how quality assurance is obtained based again from cores extracted at the structural elements exposed to the natural environment, before the construction stage ends, to reverse possible defects and take actions in order to correct them.

Nanomodified Rapid Hardening Concretes

One of the priority areas of modern construction production is the introduction of high-performance high-speed concrete with improved technological and construction-technical properties for the design, erection and repair of engineering structures. Modern studies have made it possible to view concrete from the nanoscale point of view as a material characterized by a complex hetero-scale structure of hydrated cement phases and mineral additives. The properties of concrete are determined by the type, size and nature of the interaction of the components of each structural level, which creates the possibility of nanotechnological regulation of the processes of structure formation and control of operational characteristics. The main task of nanomodification is to provide managed structure with more nanoscale hydration products. Typical nanowires in Portland cement systems are micro- and nanosilica SiO2, nanoglosses, TiO2, Al2O3, Fe2O3, CaCO3, carbon nanomaterials (carbon nanotubes and nanofibers). The introduction of C-S-H nanoparticles is the most effective way of accelerating the hydration of cement compared to other nanowires, by ensuring the growth of hydration products without an energy barrier in the pore space between the cement grains. The presented studies are devoted to the study of the nanomodification efficiency of concrete with a complex additive containing a polycarboxylate superplasticizer and synthesized nanoscale C-S-H particles. Based on the analysis of the results of early and design strength of nanomodified concrete, it is established that it is characterized by rapid strength gain and high durability after 28 days. The construction and technical properties of nanomodified concretes were investigated after 1 and 28 days of curing.

The Synergistic Effect of Secondary Raw Materials and Nano Additive on the Properties of Cement Matrix

The purpose of the research presented in this paper was to analyse the synergistic effect of nano SiO2 (NS), fluidized catalytic cracking catalyst waste (FCCCw) and calcinated at 700°C temperature paper sludge waste (PSw) on the properties the cement matrix. Nano materials are known to reduce voids between cement particles, accelerate cement hydration, and increase the strength of cement matrix. A certain amount of FCCCw and PSw in the cement mix also accelerates cement hydration and increase the compressive strength of the system, but it is important to analyse the synergistic effect of these materials on the properties of cement matrix. The results showed that both waste materials are active pozzolanic additives. The optimal quantities in terms of positive effect on the cement matrix are 10% of FCCCw and 2.5% of PSw. The paper presents the results of XRD analysis, density, ultrasonic pulse velocity and compressive strength tests with hardened cement paste. A 22% increase in compressive strength compared to the control specimen was observed in specimens where 10% of cement was replaced by FCCCw and where NS was additionally added. The replacement of cement by 2.5% of PSw increases the compressive strength about 7%. Moreover, the compressive strength of specimens containing 10% of FCCCw, 2.5% of PSw and NS increases even though the content of cement is reduced. Hardened cement paste specimens containing FCCCw, PSw, and NS have better density and ultrasonic pulse velocity values. XRD analysis showed that a combination of FCCCw, PSw, and NS added to the cement mix increases the amount of calcium hydrosilicates formed, reduces the amount of free portlandite and unreacted cement minerals (allite and belite).

The impact of diagenesis precipitation on fracture permeability in naturally fractured carbonate reservoirs

Naturally fractured carbonate reservoirs are often described as very heterogeneous systems due to the carbonate depositional environment and to the subsequent diagenesis processes such as mineral precipitation in fractures. Fluid flow behaviour in fractures is highly influenced by the fracture aperture size and its morphology. Mineral precipitation can alter the fracture effectiveness to the fluid flow and cause a partial or entire blockage of fractures. Therefore, accurate characterisation of the fracture morphology can help to enhance the prediction of the fluid flow behaviour in naturally fractured carbonate reservoirs. Mineral precipitation on fracture walls can reduce the fracture aperture significantly. As a result, the fracture permeability affected notably, which reduces the flow potential through fractures as well as changes the flow pattern. The objective of this work is to predict the flow behaviour in fractures under various levels of mineral precipitation to mimic reality. We have approached this objective by using outcrop-based models supported by a set of rock and fluid properties of a nearby fractured formation. Then, the model tested for the gas flow using the derivative plot technique of the synthetic well testing data. The simulation results have shown that mineral cementation can cause a partial blockage in fractures, hence a reduction in their flow capacity, as fractures become a less conductive medium. Nevertheless, the matrix medium can enhance the fluid flow in fractures by providing a bypass path to the fluid to overcome the sealed fractures. In this work, a formula has concluded to estimate the reduction in fracture permeability based on the fraction of the precipitated cement. In the studied formation, the core description has shown that 34% of fractures were blocked, which can lead to a reduction in the permeability by 29–64% and by 37–83% with and without matrix contribution, respectively. Thus, including the fracture morphology in the simulation model enables us to predict the performance of fractured carbonate reservoirs accurately.

A Review on Recent Advancements in Roller Compacted Concrete

Roller Compacted Concrete (RCC) is a durable material highly used for Pavements and Dams construction. In this regard being a high qualified material for its many advantages like Faster paving, Labor savings, Tax savings etc., researchers have produced many significant studies and derived the best results by various approaches. Some research includes the study of roller compacted concrete by partial replacement of cementitious minerals such as GGBS, admixtures like Glass fibres, Synthetic Fibres etc. With the help of locally available materials many tests have been conducted and results were shared to the world for further scope of study. Roller compacted concrete (RCC) has many advantages and the main attraction is its low water requirement with high workability and high compaction. This automatically results the outstanding compression strength. Current research has been focused on the improvement of mechanical properties and durability of the roller Compacted concrete incorporating different minerals and materials. In this paper, the Review of the papers have been presented in order to come to an overall understanding of the current progress for the Roller Compacted Concrete which is mainly being used for Roads, pavements, Parking lots and Dams.

Influence of the composition of cement systems on the activity of modifying additives

Modifiers of cement systems with different compositions of functional groups of polymers were studied: carboxymethylcellulose, methylcellulose, polyvinyl alcohol, polyacrylamide. The results of studies of the influence of active ions on the viscosity of aqueous solutions of water-soluble polymers using viscometry methods are presented. The influence of the type and composition of functional groups of polymer additives on the resistance to calcium, sodium and potassium ions is analyzed. It is shown that in the presence of calcium, sodium or potassium ions in the liquid phase of cement solutions, it is possible to reduce the effectiveness of polymers as stabilizers of binding systems. The most resistant to electrolytes are polymers with dominated hydroxyl groups. The composition of functional groups of water-soluble polymers and the possibility of their interaction with various ions contained in cement, aggregate, filler, in the closing water, in the composition of soils have a decisive influence on the compatibility of the polymer and the binder, the properties of cement-polymer compositions. The principles of regulating the rheological and technological properties of cement-polymer compositions, deformations of dispersed systems by selecting the rational composition of the dispersed mixture, mineral and chemical additives are given. The regularities of compatibility of components of cement systems, mineral and chemical additives in order to increase the adhesion and strength characteristics of materials based on them in the development of compositions of masonry solutions, injection and other compositions for chemical fixing of soils, in individual housing construction, in order to carry out repair and restoration work to strengthen soil bases and stone structures are presented.

Construction and technical properties of PC 500 D0 CEMENT

It is established that physical and mechanical properties of Portland cement, including setting time and strength, correspond to mark PC 500 D0 and meet technical requirements of the corresponding standard. However, they have increased dispersion ability and water consumption. It has been determined that the main Portland cement clinker minerals (C3S, β-C2S, C3A and C4AF) in cement are represented as solid solutions as a result of the presence of impurities in their structure.

Experimental study on the mechanical properties of microbial mixed backfill

Cemented backfill mining is an important technology utilized in sustainable mining practices and is fundamental in a wide variety of underground settings. However, the cement-based binder commonly used in cemented backfill materials comes at high costs, is highly alkaline, has high energy consumption, and has high carbon dioxide emissions. As an environmentally friendly technology, microbial induced carbonate precipitation (MICP) technology can produce a variety of cementitious mineral crystals to consolidate otherwise loose materials. In this paper, the MICP technology is used to replace the traditional cement-based binder frequently used in backfill mining, and the microbial mixed backfill (MMB) method is presented. The influences of various factors on the mechanical properties of MMB are also studied. It is found that the strength of MMB samples increases at first, and then decreases, when the cementation solution concentration and the volume ratio of bacterial solution to cementation solution are increased. Solids content is also an important factor that directly affects the strength of MMB samples. However, there was no obvious relationship discovered between strength variation and the total enzyme activity. In addition, different crystal morphologies of calcium carbonate, including calcite and vaterite, are observed in MMB samples. The greater the number and the denser the distribution of calcium carbonate crystals produced in the MICP reaction, the higher the strength of the MMB samples. The strength of MMB is attributed to both the amount of precipitated calcium carbonate by MICP, and the dosage of salt materials contained in the cementation solution. This research can provide basic scientific support for the application of microbial backfilling in the mining field.

Comprehensive evaluation of formation kinetics in preparation of ternesite from different polymorphs of Ca2SiO4

Ca2SiO4 is an essential intermediate phase in the formation process of Ca5(SiO4)2SO4, and the polymorph change of Ca2SiO4 would seriously influence the relevant reaction kinetics. Herein, the reaction activities of three Ca2SiO4 polymorphs (αL’, β and γ phases) in preparation of Ca5(SiO4)2SO4 are studied in detail. The results indicate there is almost no generation of Ca5(SiO4)2SO4 from αL’-Ca2SiO4, and by contrast, β- and γ-Ca2SiO4 phases can successfully form the target product. Moreover, β-Ca2SiO4 manifests a higher reactivity than that of the γ one, and the relevant reaction rate constant is about 1.6 times larger than that of the γ one. Meanwhile, the ion activation mechanism is investigated in the formation process of Ca5(SiO4)2SO4 by Eu3+ fluorescence labeling. The reaction sites containing Eu3+ ions preferentially form Ca5(SiO4)2SO4 due to the introduced oxygen defects or calcium vacancies by doping Eu3+ ions, especially for the low-temperature sintering. In combination with the polymorph influence, the activation effect from ion doping further contributes to the formation of Ca5(SiO4)2SO4. The findings in this research provide a guidance for the synthesis and application development of Ca5(SiO4)2SO4 and offer a deeper understanding of the ion doping effect in cement minerals.

Study on Preparation and Durability of Phosphogypsum Composite Cementitious Foam Concrete

Acid base salt solution erosion, carbonization test and freeze-thaw cycle test of cement foam concrete and phosphogypsum based foam concrete were carried out respectively. The results show that compared with cement based foam concrete, phosphogypsum based foam concrete has stronger performance of resisting acid and alkali salt attack. This is mainly due to the fact that its internal cement minerals and hydration products have less active components, and are not easy to react with acid-base salts, and have better ability to resist freeze-thaw cycles at the same time. However, the resistance to carbonation is not as good as that of cement based foam concrete. This is due to the high content of aluminum in the interior and the large volume of ettringite, which is easier to be carbonized.