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Specific chemical environments step out in the industry objects. Portland cement composites (concrete and mortar) were impregnated by using the special polymerized sulfur and technical soot as a filler (polymer sulfur composite). Sulfur and technical soot were applied as the industrial waste. Portland cement composites were made of the same aggregate, cement and water. The durability of prepared cement composite samples was tested in 5 per cent solution of HCl and 5 per cent solution of H₂SO₄ as a function of immersion time. The changes in mechanical strength and mass of the samples were periodically measured. Cement composites impregnated with sulfur composite exhibited limited mechanical strength and mass loss, whereas physico-mechanical properties of Portland cement concrete regressed rapidly. The loss in weight of ordinary concrete impregnated with sulfur composite, kept in aqueous solutions of acids, hydroxides, salts and in water for a year was determined using 100 × 100 × 100 mm samples. The same samples were then used in compressive strength tests.

Specific chemical environments affect industrial objects. Portland cement composites (concrete and mortar) were impregnated with a special polymerized sulfur and technical soot as a filler (polymer sulfur composite). Sulfur and technical soot were applied as industrial waste. Portland cement composites were made of the same aggregate, cement and water. The durability of the prepared cement composite samples was tested in 5 per cent solution of HCl and 5 per cent solution of H₂SO₄ as a function of immersion time. The changes in mechanical strength and mass of the samples were periodically measured. Cement composites impregnated with sulfur composite exhibited limited mechanical strength and mass loss, whereas the physico-mechanical properties of the Portland cement concrete regressed rapidly. The loss in weight of ordinary concrete impregnated with sulfur composite, kept in aqueous solutions of acids, hydroxides, salts and in water for a year was determined using 100 × 100 × 100 mm samples. The same samples were then used in compressive strength tests. The image analysis used for surface destruction monitoring, performed by scanning microscopy for the determination of damaged surface area and the original surface area before acid resistance testing, showed similar results. Based on the image analysis results, a model for predicting the degradation of mechanical strength during durability testing was established. The fact that the calculated and experimental strength values were not vastly different proved the validity of the proposed model. A brief summary of new products related to the special sulfur composite is given as follows: impregnation, repair, overlays and precast polymer concrete will be presented. Sulfur composite as a polymer coating impregnation, which has received little attention in recent years, currently has some very interesting applications.

Author comments: The article is original. The article has been written by the stated authors who are all aware of its content and approve its submission. 3. The article has not been published previously. 4. The article is not under consideration for publication elsewhere. 5. No conflict of interest exists, or if such conflict exists, the exact nature must be declared. 6. If accepted, the article will not be published elsewhere in the same form, in any language, without the written consent of the publisher.

Author comments: 1. The article is original. 2. The article has been written by the stated authors who are all aware of its content and approve its submission. 3. The article has not been published previously. 4. The article is not under consideration for publication elsewhere. 5. No conflict of interest exists, or if such conflict exists, the exact nature must be declared. 6. If accepted, the article will not be published elsewhere in the same form, in any language, without the written consent of the publisher.

The corrosion of concrete, and the factors causing or preventing it, present at least as complex a problem as metallic corrosion, and the two are frequently inter‐related. A vast tonnage of steel in all kinds of structures is protected by concrete from corrosion In the following article, the author outlines the various types of cement used in concrete, following this with a description of the chemical agents which can corrode concrete, such as organic acids, sulphates, etc. He then examines concrete as a means of preventing corrosion and also as a corrosive agent.

Investigates the characterization of cement dust collected by electrostatic precipitators and fabric filters to study its ability to be used as a concrete material. The study includes 26 cement dust samples collected from different points on dry process lines in four of the major cement plants in the United Arab Emirates. The collected samples were subjected to detailed physical tests and chemical analyses. Results obtained were compared with the British Standard Specifications set for ordinary Portland cement. Finds that eight samples show comparable physical properties and chemical as well as mineral composition.

The acceleration of corrosion of rebars in concrete are due to several reasons such as carbonation, chloride attack, influence of microorganisms, etc. The aim of this investigation mainly focused on how the microorganism was involved in the corrosion process and thereby affect a mechanical property of mortar and accelerate the corrosion of steel in mortar. ordinary portland cement (OPC) and portland pozzolona cement (PPC) was used for making mortar specimens. Sodium citrate was used as an inhibitor for the corrosion of steel in mortar.

Compressive strength measurements were conducted for mortar at different ages in the presence of microorganisms to understand the mechanical property of mortar. Potential‐time behavior studies were carried out to determine the status of rebars inside the mortar. Weight loss measurements were adopted to quantify the corrosion level due to microorganisms. The microbial count in the water samples at the initial and final exposure period was also examined.

All these studies showed that additions of sodium citrate level of greater than 1 percent by weight of OPC and PPC severely affected both the mechanical and the corrosion resistance properties of OPC and PPC. Microbiological examination reveals that bacteria consume citrates for their survival and thereby increasing the permeability of mortar specimens.

Generally, citrates are considered as being good corrosion inhibitor for steel in concrete. However, results from the present study indicated that sodium citrate concentrations only of less than 1 percent by weight of OPC and PPC are suitable for use in concretes that are exposed to heterotrophic bacterial environments.

The purpose of this paper is to investigate the mechanical properties changing of geopolymer cement under different brine salinity.

Geopolymer Cement of Class F Fly Ash and Class G Cement slurries were prepared according to API RP 10B. The optimum alkaline activator/cement and water/cement ratio of 0.44 was used for geopolymer and Class G cement samples, respectively. The alkaline activator was prepared by mixing the proportion of Sodium Hydroxide (NaOH) solutions of 8 M and Sodium Silicate (Na2SiO3) using ratio of 1:2.5 by weight. The slurries were cured for 24 hours at 130^oC and 3,000 psi in HPHT Curing Chamber followed by coring process. Both cement sample were immersed in brine water salinity up to 28 days with different brine salinity up to 30 per cent of NaCl. The mechanical properties were investigated using OYO Sonic Viewer-SX and Uniaxial Compressive Strength. The surfaces of the cement samples were extracted for Scanning Electron Microscope (SEM) and EDS tests to evaluate the morphology and chemical compositions of the cured samples.

The paper shows that geopolymer samples experiences strength reduction in brine water but the reduction rate of geopolymer is about half of the Ordinary Portland cement based oil well cement. The finding was also verified by SEM and EDS result.

This paper investigates the mechanical property changes of emerging geopolymer cement due to different water salinity. The results provide potential application of geopolymer cement for oil well cementing.

Recent advances in 3D printing construction elements have focused on ordinary Portland cement (OPC) concrete using polymeric binders; herein, this study aims to produce the same using pure water.

A binder jet printer prototype was used to fabricate specimens that are used to assess geometric and mechanical properties. Two distinct water-based binder formulations, compatible with OPC chemistry and piezoelectric jetting device, were used: pure water and water-polyvinyl alcohol (98:2 w/w) solution.

This study examines the effect of binder flow rate on dimensional accuracy. Furthermore, the changes in the mechanical properties over time with hydration have been investigated.

Results indicate that the increase in mechanical strength of Portland cement concrete with pure water was consistent; however, it was delayed by the water: PVA (98:2 w/w) solution. Post-curing by water vapor hardened the structure with the removal of layering native to 3DP and decreased infilling porosity by diffusion mechanism.

This paper has used pure water jetting for BJT of Portland cement-containing bodies.

Environmental issues caused by the production of Portland cement have led to it being replaced by waste materials such as fly ash, which is more economical and safer for the environment. Also, fly ash is a material with sustainable properties. Therefore, this paper aims to focus on the development of sustainable construction materials using 100% high-calcium fly ash and potassium hydroxide (KOH)-based alkaline solution and study the engineering properties of the resulting fly ash-based geopolymer concrete. Laboratory tests were conducted to determine the mechanical properties of the geopolymer concrete such as compressive strength, flexural strength, curing time and slump. In phase I of the study, carbon nanotubes (CNTs) were added to determine their effect on the strength of the geopolymer mortar. The results derived from the experiments indicate that mortar and concrete made with 100% fly ash C require an alkaline solution to produce similar (comparable) strength characteristics as Portland cement concrete. However, it was determined that increasing the amount of KOH generates a considerable amount of heat causing the concrete to cure too quickly; therefore, it is notable to forming a proper bond was unable to form a stronger bond. This study also determined that the addition of CNTs to the mix makes the geopolymer concrete tougher than the traditional concrete without CNT.

Tests were conducted to determine properties of the geopolymer concrete such as compressive strength, flexural strength, curing time and slump. In Phase I of the study, CNTs were studied to determine their effect on the strength of the geopolymer mortar.

The results derived from the experiments indicate that mortar and concrete made with 100% fly ash C require an alkaline solution to produce the same strength characteristics as Portland cement concrete. However, it was determined that increasing the amount of KOH generates too much heat causing the concrete to cure too quickly; therefore, it is notable to forming a proper bond. This study also determined that the addition of CNTs to the mix makes the concrete tougher than concrete without CNT.

This study was conducted at the construction engineering and management concrete laboratory at North Dakota State University in Fargo, North Dakota. All the experiments were conducted and analyzed by the authors.

Introduction How old is concrete? 150 years, 2,000 years or 9,000 years? Since the invention of Portland cement by Aspdin in the early 19th century, concrete has become the most widely used construction material in the world. Yet, concrete durability can pose severe constraints on the concrete engineer and designer. In the search for materials which are more cost‐effective or more efficient, cement replacement materials such as natural pozzolans, calcined clays, shale and soils, slags, rice husk ash or pulverised fuel ash are attracting much interest. Are these cheap replacement materials not compromising on quality and long‐term durability? A first optimistic answer is given in this paper which will be especially useful for practising civil and structural engineers, materials technologists, engineers and designers.

This study aims to investigate the optimum proportion of coconut fibre and cement suitable for rammed earth wall construction. Coconut fibres and cement can be easily incorporated into the soil mixture which adds strength and durability to the wall. This paper highlights the salient observations from a systematic investigation on the effect of coconut fibre on the performance of stabilized rammed earth blocks.

Stabilization of soil was done by adding Ordinary Portland Cement (2.5, 5.0, 7.5 and 10.0 per cent by weight of soil), whereas coconut fibre in length about 15 mm was added (0.2, 0.4, 0.6, 0.8 and 1.0 per cent by weight of soil) as reinforcement. Thirty types of mixes were created by adding different proportions of cement and fibre to locally available soil and compacting the mix at constant compaction energy in three layers with Proctor rammer.

Samples were tested for compressive strength and tensile strength, and failure patterns were analysed. The use of cement and fibre increases ultimate strengths significantly up to an optimum limit of 0.8 per cent fibre content, provides a secondary benefit of keeping material bound together after failure and increases residual strength. Benefits of fibre reinforcement includes both improved ductility in comparison with raw blocks and inhibition of crack propagation after its initial formation.

After analysing the results, it is recommended to use 0.8 per cent fibre and 5-10 per cent cement by weight of soil to achieve considerable strength. This research may add a value in the areas of green and sustainable housing, waste utilization, etc.

The purpose of this study is to advance the application of pulverised cow bone ash (PCBA) as a partial replacement of cement in soil stabilisation for the production of bricks. The study investigated the impact of PCBA substitution on the characteristic strength of clay bricks under variant curing media.

Dried cow bones were pulverised, and an energy-dispersive X-ray fluorescence test was conducted on PCBA samples to determine the chemical constituents and ascertain the pozzolanic characteristics. Ordinary Portland cement (OPC) and PCBA were blended at 100%, 75%, 50%, 25% and 0% of cement substitution by mass to stabilise lateritic clay at 10% total binder content for the production of bricks. The binder-to-lateritic clay matrixes were used to produce clay bricks and cylinders for compressive and splitting tensile strength tests, respectively.

The study found that PCBA and OPC have similar chemical compositions. The strength of the clay bricks increased with curing age, and the thermal curing of clay bricks positively impacted the strength development. The study established that PCBA is a suitable substitute for cement, up to 25% for stabilisation in clay brick production.

Construction stakeholders can successfully use a PCBA-OPC binder blend of 1:3 to stabilise clay at 10% total binder content for the production of bricks. The stabilised clay bricks should be cured at an elevated temperature of approximately 90°C for 48 h to achieve satisfactory performance.

The PCBA-OPC binder blend provides adequate soil stabilisation for the production of clay bricks and curing the clay bricks at elevated temperature. This aspect of the biomass/OPC binder blend has not been explored for brick production, and this is important for the reduction of the environmental impacts of cement production and waste from abattoirs.