Durability Of Cement Research Articles

Durability of Construction and Demolition Waste-Bearing Ternary Eco-Cements.

In recent years, the development of ternary cements has become a priority research line for obtaining cements with a lower carbon footprint, with the goal to contribute to achieve climate neutrality by 2050. This study compared ordinary Portland cement (OPC) durability to the performance of ternary cements bearing OPC plus 7% of a 2:1 binary blend of either calcareous (Hc) or siliceous (Hs) concrete waste fines and shatterproof glass. Durability was measured further to the existing legislation for testing concrete water absorption, effective porosity, pressurized water absorption and resistance to chlorides and CO2. The experimental findings showed that the 7% blended mortars performed better than the reference cement in terms of total and effective porosity, but they absorbed more pressurized water. They also exhibited lower CO2 resistance, particularly in the calcareous blend, likely due to its higher porosity. Including the binary blend of CDW enhanced chloride resistance with diffusion coefficients of 2.9 × 10−11 m2 s−1 (calcareous fines-glass, 7%Hc-G) and 1.5 × 10−11 m2 s−1 (siliceous fines-glass, 7%Hs-G) compared to the reference cement’s 4.3 × 10−11 m2 s−1. The siliceous fines-glass blend out-performed the calcareous blend in all the durability tests. As the mortars with and without CDW (construction and demolition waste) performed to similar standards overall, the former were deemed viable for the manufacture of future eco-efficient cements.

Hydration and Properties of Cement in the Belite-Ye'elimite-Ternesite System.

Energy consumption and carbon emissions are lower in the production of belite-ye′elimite-ternesite (C2S-C4A3$-C5S2$, BYT) clinker than Portland cement (PC) clinker. BYT cement can combine the early strength of CSA cements and the durability of belite cements. X-ray diffraction, mercury intrusion porosimetry, isothermal conduction calorimetry and scanning electron microscope were conducted to investigate the hydration process of BYT cement. The hydration products of BYT cement include mainly ettringite, strätlingite and some amorphous AH3 (aluminum hydroxide). Ternesite did prove an early reactivity in BYT cement. The reaction of ternesite with AH3 occurs on the surface of ternesite. Ternesite delays the second heat flow peak of ye′elimite. The strength of BYT cement containing 10% ternesite in the prepared clinker exceeds that of other cement at all ages.

Optimization of Cement–Rubber Composites for Eco-Sustainable Well Completion: Rheological, Mechanical, Petrophysical, and Creep Properties

To ensure well integrity, wellbore must be strongly cased using durable cement slurries with essential additives during downhole completion. The rubber materials that come from industrial waste are becoming extremely encouraged in the use as an additive in preparing cement slurries due to their growing environmental footprint. However, the proper design of cement slurry strongly depends on its rheological, mechanical, petrophysical, and creep properties, which can be altered by changing additives. This study aimed to examine the cement properties under alteration in different chemical admixtures to create efficient binding properties, and to estimate the optimum cement–rubber slurry composition for eco-sustainable completion. Three cement samples with different mesh sizes of the crumb rubber particles were prepared. This study examined the variation in rheological behaviors, elastic and failure characteristics, permeability, and creep behavior of the cement–rubber composites for petroleum well construction. The experimental study showed that the addition of 15% or more crumb rubber to the cement resulted in very thick slurries. Moreover, it was shown that the addition of crumb rubber with various particle sizes to the cement reduced the strength by more than 50%, especially for a higher amount of rubber added. It was also revealed that the addition of a superplasticizer resulted in an 11% increase in compressive strength. The results showed that cement–crumb-rubber composites with 12% by weight of cement (BWOC) represented the optimum composite, and considerably improved the properties of the cement slurry. Water-permeability tests indicated the addition of 12% BWOC with 200-mesh crumb rubber decreased the permeability by nearly 64% compared to the base cement. Creep tests at five different stress levels illustrated that the neat cement was brittle and did not experience strain recovery at all stress levels. Cement slurries with the largest rubber-particle size were elastic and demonstrated the highest amount of strain recovery. Finally, a relationship was established between the permeability, average strain, and mesh size of the rubber particles, which offered the strain recovery, satisfied the zonal isolation, and consequently reduced the microannulus problem to ensure the cement’s integrity.

Effects of ethylenediamine tetra-acetic acid (EDTA) and its disodium salt derivative (EDTA-Na) on the characteristics of magnesium oxysulfate (MOS) cement

Ethylenediamine tetra-acetic acid (EDTA) and its disodium salt derivative (EDTA-Na) (0.5% weight of MgO powder) were incorporated into MgO–MgSO4–H2O ternary system to prepare magnesium oxysulfate (MOS) cement. The single effect of EDTA/EDTA-Na as well as the synergistic effect of EDTA/EDTA-Na and citric acid (CA) on the hydration mechanism, phase composition, microstructure and mechanical properties of MOS cement were investigated. The results showed that EDTA and EDTA-Na addition induced no new phase, but the magnesium-EDTA complexes formed by EDTA4− and Mg2+ ions acted as nuclei for the hydration products, including brucite, 3 Mg(OH)2·MgSO4·8H2O (318 phase) and 5 Mg(OH)2·MgSO4·7H2O (517 phase). This helped to form a more homogeneous and compact microstructure, thereby improving the durability and volume stability of MOS cement in air curing condition. Moreover, the synergistic effect of EDTA/EDTA-Na and CA preferred the formation of 517 phase to that of brucite. It further improved the water resistance of MOS cement. In this study, EDTA and EDTA-Na were found to be effective additives in improving the characteristics of MOS cement.

Strength and Durability of Cement Stabilized Expansive Soil Amended with Sugarcane Press Mud

The present investigation delved into the performance of cement stabilized soil amended with sugarcane press mud (PM), an organic waste residue from the sugar industry. An expansive soil was stabilized using 3% and 8% ordinary Portland cement (OPC) and modified with 1%, 3% and 5% PM. Cylindrical samples of dimensions 38 mm diameter and 76 mm height were cast and cured for 7, 14 and 21 days for all combinations considered. After the designated curing periods, the specimens were strained axially until failure to determine the strength of the samples. Samples were also subjected to alternate cycles of wetting and drying and the resistance to loss in weight was determined. The results of the investigation revealed that PM can be considered as a strength accelerator due to enhancement in early strength of the samples at 7 days of curing but beneficial strength gain could not be sustained over extended curing periods considered. However, 1% and 3% PM modified specimens were more resistant to weight loss when compared to pure cement stabilized specimens. Based on the results of the investigation, PM can be considered as a potential auxiliary additive to cement stabilized soil for improving the durability performance of the soil.

Recent developments in reactivity testing of supplementary cementitious materials

Identification and rapid characterization of novel supplementary cementitious materials (SCMs) is a critical need, driven by shortfalls in conventional SCMs. In this study, we present a discussion of recently developed reactivity tests – the R3 test, the modified R3 test, the lime strength test, and the bulk resistivity index test. These tests measure reactivity parameters such as heat release, bound water, calcium hydroxide consumption, strength, and bulk resistivity. All tests can screen inert from reactive materials. To additionally differentiate pozzolanic and latent hydraulic materials, two parameters, for example, calcium hydroxide consumption and heat release, are needed. The influences of SCM bulk chemistry, amorphous content, and fineness on measured reactivity are outlined. Reactivity test outputs can predict strength and durability of cement paste/mortar/concrete; however, caution must be exercised as these properties are influenced by a variety of other factors independent of reactivity. Thoughts are provided on using reactivity tests to screen materials for concrete durability.

Assessment of compressive strength, durability, and erodibility of quarry dust-based geopolymer cement stabilized expansive soil

Assessment of compressive strength, durability, and erodibility of quarry dust-based geopolymer cement stabilized expansive soil

Durability of Ternary Cements Based on New Supplementary Cementitious Materials from Industrial Waste

Cement-based materials decay with exposure to aggressive agents, a development that raises infrastructure operation and maintenance costs substantially. This paper analyses the inclusion of ultrafine construction and demolition (UC&DW) and biomass-fuelled power plant (BA) waste as pozzolanic additions to cement in pursuit of more sustainable and eco-respectful binders and assesses the durability of the end materials when exposed to seawater, chlorides (0.5 M NaCl) or sulphates (0.3 M Na2SO4). The effect of adding silica fume (SF) at a replacement ratio of 5% was also analysed. Durability was determined using the methodology proposed by Koch and Steinegger, whilst microstructural changes were monitored with mercury intrusion porosimetry (MIP), X-ray diffraction (XRD) and scanning electron microscopy (SEM) for a fuller understanding of decay processes. According to the findings, the new blended cements containing 20%UC&DW + 10%BA or 20%UC&DW + 20%BA + 5%SF resist the attack by the aggressive media studied, with a 56-d corrosion index of over 0.7. The composition of the reaction products generated with the attack is essentially the same in OPC and the SCM-bearing materials. The results show that the optimal replacement ratio for SCM is 30%.

The Influence of Glass Fiber and Milled Glass Fiber on the Performance of Iraqi Oil Well Cement

The reinforced fiberglass in cement slurry reflects the effect on its properties compared to usual additives. Fiberglass is typically used in cement slurry design for one or another of the following goals: (Earth earthquake, bearing storage, and with differential stresses, to enhance cement durability and increase its compressive strength). The main goal is to use glass fiber and ground fiberglass to improve the tensile strength and moderate compressive strength significantly. On the other hand, the use of glass fibers led to a slight increase in the value of thickening time, which is a desirable effect. Eleven glass fiber samples and milled glass fiber were used to show these materials' effect on Iraqi cement with (0.125, 0.25, 0.5, 0.75, 1, and 2) % of cement weight. Those tests used to study cement slurry‟s following properties were compressive strength, thickening time, rheology properties of free water, filtering, and density. These evaluations showed that slurries with less than 1% fiber content gave a higher compressive strength than a sample containing more than 1% glass fiber. However, the slurry mixed with equal or less than 1% milled glass fiber is higher compressive than the sample mixed with more than 1% milled glass fiber. So the optimal concentration for glass fiber is less than 1% by weight of cement (BWOC); either for milled glass fiber, it is less or equal to 1% BWOC. Both materials contributed to increasing the compressive strength of the cement. However, attention must be paid to the idealThis work is licensed under a Creative Commons Attribution 4.0 International License.
 concentration that should be added during the cement slurry preparation because if we use these two materials carelessly for the ideal concentration, this leads to the collapse and bombardment of the resistance of the cement rock. In other words, the collapse of cement resistance and causing problems during the cementing process.

Durability of Cement and Ash Mortars with Fluidized and Siliceous Fly Ashes Exposed to HCl Acid Environment over a Period of 2 Years.

The paper presents results of research on the impact of fly ash from fluidized bed combustion (FBC) of lignite, used in quantities of 30 and 45% by mass, and the mixture of FBC and silicious fly ash in amount of 45% by mass, on properties of cement–ash mortars. Mortars were exposed to aggressive environment of 1, 3, and 5% HCl solutions for 2 years. Mortars containing 45% FBC exposed to 1% HCl solution (pH = 2) showed the highest durability from among other mortars. The growth of their strength observed after 90 days of testing in 1% HCl environment, as well as the lowest drop of strength after 730 days of exposure to this environment, resulted from the reduced amount of large pores from 20 to 200 nm in mortars containing fly ash, with simultaneous growth of smaller pores of <20 nm during testing. A beneficial effect has been demonstrated of FBC addition to cement on properties of cement–ash mortars exposed to the aggressive impact of the HCl. Mortars with FBC fly-ash content increased to 45% by mass showed higher strength values, smaller differences in linear and mass changes, and increased durability in an aggressive environment observed during 730 days of testing.

Impact of Fly Ashes from Combustion in Fluidized Bed Boilers and Siliceous Fly Ashes on Durability of Mortars Exposed to Seawater and Carbonation Process.

This article presents test results of aggressive environment impact, i.e., seawater, acid solutions and carbonation, on the durability of cement–ash mortars. Tests were conducted on CEM I 42.5R-based mortars containing 35 to 70% by mass of FBC fly ash from brown and black coal combustion in a homogeneous form and mixtures of 35% by mass of siliceous fly ashes (CFA) and 35% by mass of FBC fly ash. It was demonstrated that in normal conditions (20 °C), FBC ashes showed higher pozzolanic activity than CFA, except when their curing temperature was increased to 50 °C. FBC ashes increased mortars’ water demands, which led to an accelerated carbonation process. In an environment of Cl- ions, cement–ash mortars showed more Ca2+ ions leached and no expansive linear and mass changes, which, with their increased strength, might be an argument in favour for their future use in construction of coastal structures resistant to seawater. FBC ash content may be increased to 35% by mass, maintaining mortars’ resistance to seawater, acid rain and carbonation. A favourable solution turned out to be a FBC and CFA mixed addition to cement of 35% by mass each, in contrast to mortars containing 70% of FBC fly ash in homogeneous form.

Sulfate and Chloride Resistance Properties of Portland Cement Blends

About 53% area of Bangladesh is alluvial deposited and affected by sulfate, salinity and chloride in water and soil. Existing sulfate and chloride can severely damage the building in coastal regions. In this paper durability of cement is evaluated on the basis of strength of mortar cube, concrete cylinder test. Besides the sulfate resistance is measured by change of length of the mortar bar specimens during exposure to sulfate solution and the attacking chloride properties by Rapid chloride ion penetration test using OPC, PCC, 20% FA, 30% FA and 40% FA. The strength was observed in cube sample about 40.65, 37.2MPa after 13 weeks in sulfate solution and linear expansion was obtained about 0.28% and 0.133% for OPC and PCC cement with reference to the water. The compressive strength of the cylindrical specimens was about 16.96, 18.34 MPa for OPC and PCC, respectively at the age of 28 days. The permeability of chloride ion of OPC sample was 22.8% higher than the PCC at this age.&#x0D; Journal of Engineering Science 12(1), 2021, 69-75

Strength properties of double blend and triple blend self-compacting concrete subjected to different curing methods

The behaviour of Self Compacting Concrete is complex with the addition of both chemical and mineral admixtures. The use of supplementary cementing materials such as Metakaolin, FlyAsh, GGBS and Silica fume is required to improve the flow properties of fresh concrete, to decrease the cement contents, to increase the strength as well as durability of cement and to reduce cement consumption for environmental and economical concern. The hydration mechanism, strength, and setting characteristics of SCC are all influenced by the curing process. As a result, the findings of an investigation into the effects of curing methods on the compressive strength of SCC using Metakaolin as the primary supplementary cementing material are described in this paper. FlyAsh, GGBS and Silica fume are used individually for triple blend binders with OPC and Metakaolin. The Grade of concretes made were Standard concretes of M50. The concretes’ compressive strengths were assessed at 7 and 28 days. The traditional water pond approach was used as a reference, and wax-based liquid membrane and polymer-based liquid membrane curing compounds were used for testing. To reduce the water cement ratio and increase the flow and filling capacity of SCC, a superplasticiser based on a polycarboxylic ether polymer with long lateral chains is used. The performance of the Polymer based membrane curing compound is better than Wax based membrane curing compound. In addition to this, the polymer based membrane allows plastering and painting over the concrete surface. The early gain in strength is observed in all the membrane cured cubes at 7 days, but the rate of gaining strength is reduced after 7 days when compared with the Water pond cured cubes.

Bond durability of epoxy and cement- bonded CFRP reinforcement to concrete interfaces subject to water immersion

Durability is a critical concern for concrete structures externally bonded with fiber-reinforced polymer reinforcement. This paper presents the results from an experimental study which compared the bond durability of epoxy-bonded CFRP sheets and cement-bonded CFRP grids to concrete interfaces subjected to water immersion. Totally twelve groups of CFRP sheet or grid-strengthened concrete beams with a notch at their midspan were carefully fabricated through epoxy- and cement-based bonding systems and tested under monotonic loading before and after water immersion exposure, respectively. The cement binder included polymer cement mortar (PCM) and ductile engineered cementitious composite (ECC). The CFRP grids and sheets were designed with the similar tensile stiffness. The duration of water immersion ranged from 0 to 6 months. The test results indicated that debonding in concrete adjacent to the concrete-adhesive interface in accompany with a diagonal concrete crack near the notch was the main failure mode of the beams strengthened with epoxy-bonded CFRP sheet and ECC-bonded CFRP grid, while the tearing off of CFRP grids from the PCM matrix was the main failure mode of the beams strengthened with PCM-bonded CFRP grids. After water immersion exposure, the ultimate loads of the beams with cement-based CFRP grids were at least 50% higher than their epoxy-bonded counterparts, confirming the superior moisture durability of cement based bond to epoxy-bonded ones. The interfacial fracture energy was found to exhibit an exponential decline trend with water immersion duration.

Mechanical and Durability Properties of Portland Limestone Cement (PLC) Incorporated with Nano Calcium Carbonate (CaCO3).

Despite lower environmental impacts, the use of Portland Limestone Cement (PLC) concrete has been limited due to its reduced later age strength and compromised durability properties. This research evaluates the effects of nano calcium carbonate (CaCO3) on the performance of PLC concrete. The study follows a series of experiments on the fresh, hardened, and durability properties of PLC concrete with different replacement rates of nano CaCO3. Incorporation of 1% nano CaCO3 into PLC concrete provided the optimal performance, where the 56 days compressive strength was increased by approximately 7%, and the permeability was reduced by approximately 13% as compared to Ordinary Portland Cement (OPC) concrete. Further, improvements were observed in other durability aspects such as Alkali-Silica Reaction (ASR) and scaling resistance. Additionally, nano CaCO3 has the potential to be produced within the cement plant while utilizing the CO2 emissions from the cement industries. The integration of nanotechnology in PLC concrete thus will help produce a more environment-friendly concrete with enhanced performance. More in-depth study on commercial production of nano CaCO3 thus has the potential to offer a new generation cement—sustainable, economical, and durable cement—leading towards green infrastructure and global environmental sustainability.

The Hydration, Mechanical, Autogenous Shrinkage, Durability, and Sustainability Properties of Cement–Limestone–Slag Ternary Composites

This study examines the hydration–mechanical–autogenous shrinkage–durability–sustainability properties of ternary composites with limestone filler (LF) and ground-granulated blast furnace slag (BFS). Four mixtures were prepared with a water/binder ratio of 0.3 and different replacement ratios varying from 0 to 45%. Multiple experimental studies were performed at various ages. The experimental results are summarized as follows: (1) As the replacement levels increased, compressive strength and autogenous shrinkage (AS) decreased, and this relationship was linear. (2) As the replacement levels increased, cumulative hydration heat decreased. At the age of 3 and 7 days, there was a linear relationship between compressive strength and cumulative hydration heat. (3) Out of all mixtures, the ultrasonic pulse velocity (UPV) and electrical resistivity exhibited a rapid increase in the early stages and tended to slow down in the latter stages. There was a crossover of UPV among various specimens. In the later stages, the electrical resistivity of ternary composite specimens was higher than plain specimens. (4) X-ray diffraction (XRD) results showed that LF and BFS have a synergistic effect. (5) With increasing replacement ratios, the CO2 emissions per unit strength reduced, indicating the sustainability of ternary composites.

Evaluation of the influence of ambient air temperature and air velocity on mortar cement durability using a forced convection solar dryer

PurposeThis work aims to study the hydrothermal behavior of mortar cement toward certain environmental factors (ambient air temperature and air velocity) based on its drying kinetics data. The objective is to provide a better understanding and controlling the stability of mortar structures, which integrate the sorption phenomenon, drying process, air pressure and intrinsic characteristics. This leads to predict the comportment of mortar structures in relation with main environmental factors and minimize the risk of cracking mortar structures at an early age.Design/methodology/approachThermokinetic study was carried out in natural and forced convection solar drying at three temperatures 20, 30 and 40°C and three air velocities (1, 3 and 5 m.s-1). The empirical and semiempirical models tested successfully describe the drying kinetics of mortar. These models simulate the drying process of water absorbed by capillarity, which is the most common humidity transfer mechanism in building materials and contain parameters with physical significance, which integrate the effect of several environmental factors and intrinsic characteristics of mortar structures.FindingsThe models simulate the drying process of water absorbed by capillarity, which is the most common humidity transfer mechanism in building materials and contain parameters with physical significance, which integrate the effect of several environmental factors and intrinsic characteristics of mortar structures. The average activation energy obtained expressed the temperature effect on the mortar diffusivity. The drying constant and the diffusion coefficient can be used to predict the influence of these environmental factors on the drying behavior of various building materials and therefore on their durability.Originality/valueEvaluation of the effect of several environmental factors and intrinsic characteristics of mortar structures on their durability.

Expansion Mechanism and Properties of Magnesium Oxide Expansive Hydraulic Cement for Engineering Applications

The expansion mechanism of magnesium oxide expansive hydraulic cement as a novel expansive hydraulic cement was reviewed. Anisotropic crystallization results in crystal growth pressure, causing volume expansion while also increasing the porosity of the whole system. The theoretical relationship between porosity and expansion was analyzed. A basic method is given for predicting the expansion rate considering the expansive agent content in MgO expansive hydraulic cement. A concise equation is proposed for calculating the ultimate expansion. A theoretical relationship between porosity and expansion is presented. The compressive strength and durability of magnesium oxide expansive hydraulic cement were analyzed considering porosity changes and compared with hydraulic cement. If the expansion rate exceeds 0.8%, the mechanical properties and durability changes caused by porosity should be considered. If magnesium oxide expansive concrete is used with restraining in real structure, extra compressive stress is generated and the porosity decreases, compared with that during free expansion. In particular, for strain‐hardening cementitious composites, expansion confined with the fibers present in the composite is beneficial for refining cracks and improving the self‐healing ability of these materials whenever exposed to humid environments. This paper describes the expansion mechanism and properties of magnesium oxide expansive hydraulic cement for engineering applications.

Influence of Rice Husk Ash on Characteristics of Earth Cement Blocks

AbstractThis paper presents an experimental study on the characteristics of earth cement blocks with Rice Husk Ash (RHA) as a partial replacement to cement. The replacement of RHA content is limited to 0%, 5%, 10%, 15% and 20% by mass of the total binder in the earth cement block. The experiments on earth cement blocks investigate the compressive strength and flexural tensile strength for mechanical properties and water absorption, sorption rate and erosion against water spray for its durability. Due to the high content of SiO2 in RHA with great reactivity, a significant increase in the compressive and flexural tensile strength of earth cement blocks was observed up to 10% RHA content. However, the durability of earth cement blocks becomes adverse with the increasing percentage of RHA replacement, but within the allowable limit. The experimental results indicate that to some extent, RHA based earth cement blocks have a significant potential for reduction in cement used in the construction industry.

EXPERIMENTAL STUDY OF MICRO SILICA BEHAVIOR AND ITS EFFECT ON IRAQI CEMENT PERFORMANCE BY USING X-RAY FLUORESCENCE ANALYSIS

The cement slurry is a mixture of cement, water and additives which is established at the surface for injecting inside hole. The compressive strength is considered the most important properties of slurry for testing the slurry reliability and is the ability of slurry to resist deformation and formation fluids. Compressive strength is governed by the sort of raw materials that include additives, cement structure, and exposure circumstances. In this work, we use micro silica like pozzolanic materials. Silica fume is very fine noncrystalline substantial. Silica fume can be utilized like material for supplemental cementations for increasing the compressive strength and durability of cement. Silica fume has very fine particles size less than 1 micron and by an average of about 0.1 microns, about 100 times slighter than particles of cement. We are adding 0%, 5%, 10%, 15%, 20% and 25% micro silica by wt. of cement. The results showed that adding micro silica enhance the performance of Iraqi cement but also leads to a slight decrease in thickening time. To avoid this problem, super plasticizer is used to make the process of cement pumping more easily, in other words, increase thickening time and increase compressive strength. The experimental work showed that adding micro silica leads to reduce free water and this property is very important through horizontal drilling. X-ray fluorescence technique delivers beneficial elemental information about the chemical structure of Iraqi cement to help us use it without causing damage through the cementing job. In this paper, some outlines of the XRF device and its main applications are presented. By using X-ray fluorescence analysis, we detect the problem of Iraqi cement and solve it in this paper to use it at cementing jobs in the Iraqi field instead of using imported cement.