Portland Cement Composites Research Articles

Underwater fatigue behavior of cementitious mortar and a countermeasure using a water-dispersible polyurethane ether–Portland cement composite

The underwater fatigue behaviors of cementitious mortars are investigated with a focus on the mechanisms contributing to the deterioration of bridge foundations and possible countermeasures. This study analyzes the effects of water penetration during repetitive loading and unloading on the underwater fatigue lives of cementitious materials, highlighting the importance of considering dynamic water motion, in addition to the surface energy mechanism. Water penetration during underwater fatigue occurs even in water-saturated specimens, and water in- and egress within a few millimeters of the specimen surface can significantly reduce the fatigue life. This study proposes a novel approach using a water-dispersible polyurethane ether–Portland cement composite as a countermeasure to improve underwater fatigue resistance. Based on experimental analysis of fatigue in water and microstructural investigations of the composite, the presence of polyurethane compounds within the nano-to-micron-sized microstructures may mitigate water penetration and contribute to a corresponding increase in underwater fatigue life.

Experimental and Numerical Investigations of the Effect of Curing Conditions on the Temperature Rise of Concrete

This paper presents experimental and numerical studies investigating the impact of three curing conditions on temperature evolution in concrete cubes. The tests were performed on samples of the same volume (3.375 dm3) under different curing conditions: room temperature, insulation boxes, and adiabatic calorimeter. Various cements (Portland cement, Portland composite cement, and blast furnace slag cement) and aggregates (gravel and basalt) were examined. The temperature evolution for all mixtures was analyzed, revealing a correlation between temperature increase and concrete type. Under insulation and adiabatic curing, Portland cement with gravel aggregate exhibited the highest temperature rise, while blast furnace slag cement with basalt aggregate showed the lowest increase. The incorporation of slag, ash, or other mineral additives reduced temperature rise. Additionally, basalt aggregate’s higher heat capacity and thermal energy accumulation led to a decreased temperature increase compared to gravel. Using recorded thermal data, a numerical procedure predicting temperature development in nonadiabatic conditions through direct adiabatic tests is proposed. Comparisons between experimental and numerical temperature evolutions confirmed the model’s accuracy.

Use of synthetic calcium hydrosilicate in Portland cement compositions

We investigated the patterns of the synthesis of calcium hydrosilicate of tobermorite composition in the "amorphous silica–calcium hydroxide–water" system. The gradual interaction of calcium hydroxide and amorphous silicon(IV) oxide leading to the formation of synthetic tobermorite was confirmed by X-ray diffraction analysis. It was determined that the optimal duration of the synthesis of calcium hydrosilicate was 5 days, which, according to electron microscopic studies, ensured the production of grains with a size of 0.4–4 m. The influence of the synthesized tobermorite on the change in strength characteristics of cement stone during setting was studied using cement-sand mortar mixtures with sands of different particle size distribution. A comparative analysis of the effect of storage conditions of the synthesized product on the structure-forming processes of cement stone was carried out. It was established that the modifying effect of synthetic tobermorite was observed when it was dried after synthesis and stored in a dry state. Conversely, prolonged storage of calcium hydrosilicate in a wet state led to a loss of its activity and a decrease in the strength characteristics of cement stone. The mechanism of the influence of calcium hydrosilicate additive was studied by measuring the change in the rate of heat release of cement dough at the initial stage of hydration. It was shown that the addition of dry calcium hydrosilicate accelerated the physicochemical processes of hydration of clinker minerals, while the addition stored in wet conditions slowed down hydration. Electron microscopic studies of cement stone after 28 days of setting confirmed that the introduction of dry calcium hydrosilicate contributed to the formation of a structure characterized by a higher degree of crystallization and an increase in the strength of the samples.

The effect of the combined addition of copper, lithium and sulphur on the formation of Portland cement clinker.

Both copper and lithium act as strong fluxes and lower the temperature of the clinker melt formation. Sulphur promotes the stabilisation of more hydraulically active modification of alite M1. It is expected that this combination could produce an alite clinker at significantly lower temperatures with high quality technological parameters. In this paper, the effect of combined oxides of copper, lithium and sulphur addition on the phase composition and clinker structure of Portland cement was investigated. The reference raw meal was prepared from common cement raw materials. Each of the mentioned oxides was added to the reference raw meal in two different concentrations, and 8 combinations were prepared. Chemically pure compounds (NH4)2SO4, CuO and Li2CO3 were used as a source of these oxides. The raw meals were burned to equilibrium at 1450°C. Their phase composition was determined by X-ray diffraction analysis, the microstructure was monitored by optical microscopy, and the microchemistry of the clinker phases was observed by electron microscopy with EDS analysis. It was found that in samples with high lithium or copper content, there is an increase in belite and free lime at the expense of alite. The combination of Cu + Li has the most negative effect, followed by Li alone and Cu alone. The higher SO3 content slightly offsets this negative effect.

Compressive Strength of Palm Ash Geopolymer Mortar against High Temperatures

Palm ash geopolymer mortar is an alternative material that can be used in construction materials. This study to analyze the physical characteristics of palm ash geopolymer mortar against the effects of high temperatures. The mortar sample will be designed with a geopolymer mixture consisting of sand, palm ash, alkaline activator solution (NaOH and Na2SiO3) as an adhesive paste to replace cement. The geopolymer composition will take into account the effect of palm ash with an alkaline activator solution, so the optimal composition will be a sample size of 5x5x5 cm. Then the sample is put into the oven furnace to give high temperature effect on the mortar with temperature variations of 100°C, 200°C, and 300°C, and a mixture of 10%, 20%, 30% portland composite cement substitution by weight of palm ash. The results on the temperature variation of the maximum value of compressive strength occurred at 200°C with 20% cement variation and the minimum compressive strength results occurred at 100°C for 10% cement variation. The effect of high temperature will have an effect on visually different physical characteristics. These resulted in the composition of the palm ash geopolymer components which would affect high temperatures which resulted in changes in the physical characteristics of the palm ash geopolymer mortar.

Preparation and mechanical properties of Portland cement composites filled with bamboo fibres modified by acetic acid and fermentation treatment

To improve the compatibility between Portland cement and bamboo fibre, bamboo fibres were modified by acetic acid and fermentation treatment and the modified bamboo fibres/Porland cement composites were prepared. The hydration curves of the bamboo fibres/Porland cement composites were measured and the area ratio under the cement hydration heat curve was used as the compatibility coefficient to evaluate the compatibility of bamboo fiber and cement. The hydration products at different hydration times were characterized by XRD, FTIR, and SEM. Moreover, the mechanical strengths of standard test blocks of Portland cement/bamboo fibre composites were tested to further verify the improved compatibility of bamboo fiber and Portland cement. The study shows that the compatibility between bamboo fibre and Portland cement was improved from 9% to 87%, the bending strength of Portland cement/bamboo fibre composite was increased from 638 N to 3678 N, and the compressive strength was increased from 1.5 MPa to 34.35 MPa.

Use of creep and recovery protocol to assess the printability of fibre-reinforced 3D printed white Portland cement composites

ABSTRACT White Portland cement is an ideal choice for producing 3D printed coloured composites due to its inherent whiteness. However, the uncontrollable rheological properties limit the establishment of printed structures and thus affect the mechanical properties. In this study, the polyvinyl alcohol (PVA) and polypropylene (PP) fibres were utilised as reinforcement materials in 3D printed white Portland cement composites (WPCCs) to improve the printability and toughness by controlling creep properties, aiming to build better printed structures. Experimental results show that the addition of PVA and PP fibres effectively improve the creep properties of WPCCs, and printed structures can be well built by controlling creep properties. Specifically, the thixotropy of WPCCs with PVA and PP fibre is improved within specific content ranges of 0∼1% and 0.4∼0.8%, respectively. Compared with reference sample, the flexural strength increases by approximately 148.8% and 90.2% when the PVA and PP fibre contents reach 1.25% and 1%, respectively.

Characteristics of palm oil fuel ash concrete admixed with precipitated silica and silica fume

This study investigates the characteristics of blended Palm Oil Fuel Ash (POFA) concrete admixed with silica fume (SF) and precipitated silica (SP) as a cement replacement material for Portland Composite Cement (PCC). The study aims to evaluate the potential of precipitated silica extracted from POFA as an alternative to commercial silica fume in enhancing the properties of palm oil fuel ash concrete. Four different mixes were studied, including a control mix with PCC and three mixes with varying amounts of POFA, SF, and SP. The study analyzed the fresh properties, compressive strength, strength activity index, tensile strength, and microstructure of the concrete. The results showed that the addition of SF and SP increased the compressive strength of the POFA concrete by 23.34% and 38.11% respectively at 28 days. The strength activity index was also higher in the mixes with silica, indicating a higher pozzolanic activity at early ages. The tensile strength and porosity of the concrete were also improved with the addition of silica. The SEM and FTIR analysis confirmed that the addition of silica, especially precipitated silica, improved the microstructure of the concrete. The study concludes that the precipitated silica from POFA has the potential to be used as a cement replacement or additive in POFA concrete manufacturing in Asian countries where POFA is abundantly available.

Effect of variations in concrete quality on the crack width in rigid pavement

Cracks pose a significant issue in rigid pavement, leading to substantial damage. The manual mixing and casting of road pavement concrete underscore the importance of concrete quality as a critical parameter. This study investigates crack behavior by varying concrete quality. Loading is performed statically using line loads, shedding light on the impact of concrete quality on crack development. The concrete to be used has a quality fc' of 15 MPa, 25 MPa, and 35 MPa. The fine aggregate used in this study was Lumajang black sand, while the coarse aggregate used was machine crushed stone, and Portland Composite Cement (PCC) was used in all concrete mixes. The reinforcing steel used had a quality fy of 480 MPa, with a reinforcement ratio of ρ=0.010, which was converted to 5-D16 reinforcement. The subgrade density used to support the specimens had a CBR value of 10 %. Specimen dimensions were 2×0.6×0.2 m for length, width, and thickness. Pavement plates, 30 cm thick, were placed on leveled subgrade soil in a steel box set to achieve a 6 % CBR reading. Hydraulic jacks, monitored by a load cell, applied monotonic static loading with 2 kN intervals, reaching a maximum load of 200 kN. Steel tension and plate settlement were measured using a tension sensor and Linear Variable Differential Transformer (LVDT), respectively. A data logger recorded readings, and crack widths were captured by a digital microscope with 0.01 mm accuracy. Experimental results show that low concrete compressive strength values result in larger crack widths, and vice versa. Cracks also occur at earlier loading of concrete quality fc' 15 MPa. In addition, experiments show that the reinforcement stress value has a significant influence on crack width in specimens with low concrete quality

Influence of Nano-Fly Ash on mechanical properties, microstructure characteristics and sustainability analysis of Alkali Activated Concrete

Ordinary Portland Cement (OPC) composites significantly affect the atmosphere by emitting Carbon dioxide (CO2) during its production process. The addition of Nano Materials (NM) for the construction could change the matrix configuration at the nano level. Compared to other NMs, converting industrial by-products and locally available materials into nano size can enhance the characteristics of the binder composites. This research work focuses on the effects of Nano Fly ash (nFA), on the fresh, mechanical, microstructural, and thermal resistance properties of Fly Ash (FA) and Ground Granulated Blast Furnace Slag (GGBFS) based Alkaline Activator Nano Concrete (AANC). The impact of adding nFA in various concentrations of 3 %, 6 %, 9 %, 12 %, and 15 % on the properties of AANC was studied. By adding nFA in an optimal proportion, the degree of geo-polymerization is improved which is found by Field Emission Scanning Electron Microscopy (FESEM), X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Energy Dispersive X-Ray Analysis (EDAX) and Fourier Transform Infrared (FTIR). Results indicate that the addition of nFA significantly increased polymerization, reducing initial and final setting times by 13.3 %–52.5 % and 5.3 %–28.8 %, respectively. Moreover, nFA promoted the formation of polymer gel, leading to a denser microstructure with fewer cracks and refined pores, resulting in a substantial increase in mechanical strength, particularly with 9% nFA, achieving an optimal CS of 56.14 MPa after 28 days which is 37.97 % improvement compared to the mix without nFA. However, when nFA was added, beyond 9 %, the performances declined due to its high surface area resulting in a non-uniform dispersion that promoted agglomeration. This dispersion enhances the formation of C-A-S-H and C–S–H gels. The addition of nFA in AANC can be an environmentally friendly solution by reducing CO2 emissions, energy consumption, cost reduction and increased sustainability.

Optimization of a mixture of lime and portland composite cement (PCC) for stabilizing peat soil in road construction

Peat soil presents significant challenges in construction due to its low bearing capacity and high compression. Several soil improvement methods are available to address these issues. One viable approach to enhancing soil quality is through lime and cement stabilization. This research aims to investigate the impact of a lime and cement mixture on the physical and mechanical properties of the soil at the research location. The research results reveal that the CBR (California Bearing Ratio) value for the original soil is 5.60%. CBR values increased in specific mixture variations, with the CBR value for the original soil + 3% lime + 5% cement mixture reaching 11.56%. This mixture can be employed in the subgrade, meeting the CBR requirement for road construction subgrade, which is 6%. In the case of the mixture involving the original soil + 10% lime + 10% cement, a CBR value of 26.50% was achieved. The CBR value for subgrade with outstanding criteria for road construction is 20% to 30%. The addition of a lime and cement mixture for peat soil stabilization can significantly enhance the soil's bearing capacity, and increasing the percentage of lime and cement in the mixture leads to higher CBR values.

Estimation of Physical and Mechanical Properties of Portland Composite Cement Produced by Using Raw Perlite with Fuzzy Logic Model

Estimation of Physical and Mechanical Properties of Portland Composite Cement Produced by Using Raw Perlite with Fuzzy Logic Model

Comparative study of the use of Ordinary Portland Cement (OPC), Portland Composite Cement (PCC) and Hydraulic Cement (HC) types in high quality concrete with an independent compaction system

One of the problems faced in the manufacture of high-strength concrete is the difficult workability, and the rising price of OPC and PCC cement. To overcome these problems, a self-compacting system is needed in concrete to make the workability easier to work with and the use of other types of cement besides OPC and PCC, such as the latest product HC, to reduce the cost of making high-strength concrete. The objective of this study was to compare the use of OPC, PCC and HC cement types in high strength concrete with self-compacting system, so as to overcome the high-quality problem more effectively. The manufacture and testing of test specimens were carried out at the PT Pionir Beton Industri Laboratory with the results of testing the compressive strength of OPC type cement at 955.93 kg/cm2, the compressive strength of PCC cement concrete at 866.22 kg/cm2, and the compressive strength of HC cement concrete at 885.83 kg/cm2. It can be concluded that the use of OPC cement in concrete mixes will produce the strongest concrete among the other two types of cement.

Comparison of types of grouting to guarantee zero tendon slip with post-tension system prestressed concrete bridge anchors

Prestressed concrete is internal stresses of appropriate magnitude and distribution are given in such a way that the stresses caused by external loads are resisted to a desired level. The use of prestressed concrete is mostly applied in bridge construction, especially in the bridge girders. During the stressing girder process, grouting is carried out to prevent the anchor from slipping. The strength of the adhesion of the grouting material used determines the homogeneous nature and whether the prestressed concrete section next to it can meet the anchor load. If the bond strength does not meet the requirements, it will cause slippage in the anchors which will ultimately affect the strength of the prestressed concrete structure due to quite large prestress losses due to slippage. The method used is to test the adhesive strength of the strands that have been grouted with f.a.s. 1:3 using each grouting material such as PCC (Portland Composite Cement), PPC (Portland Pozzoland Cement), OPC (Ordinary Portland Cement) and Sika Grout 215 which is then compared with the grouting material that adheres best. The results obtained were Sika Grout 215 bond strength of 3.6629 MPa, PCC bond strength of 3.2986 MPa, PPC bond strength of 2.5743 MPa and OPC bond strength of 2.307MPa.

Compressive Strength of Corn Stalk Ash as Supplementary Cementitious Material in Mortar

The availability of agricultural wastes, especially corn stalks, offers sustainability benefits in reducing the demand for cement production. Altering this waste into ash becomes significant for cementitious material. Thus, the study utilized corn stalk ash (CSA) as a partially cementitious material in producing cement mortar. This experimental study aims to understand the compressive strength of CSA mortar samples and their characteristics, such as absorption and their correlation. Compressive strength and absorption tests were performed in the laboratory to specimen control (M0) and partial replacement of CSA to Portland Composite Cement (PCC) at different portions of 5%, 10%, and 15% or M5, M10, and M15 at 7d, 28d, and 56d. Before mixing, we measured cement and fine aggregate (sand) properties with a water-to-binder ratio (w/b) of 0.48, based on the standard reference in producing an ordinary mix mortar. The CSA used came from an agricultural field around central Java known to have good pozzolanic reactivity. Then, the average compressive strength and weight change were measured. The results indicate that the optimum increase in compressive strength of mortar was achieved with a 10 percent CSA replacement, which exhibited 96% enhancement from 7 to 28 days compared to other mixes. In addition, the weight changes of the mortar mix have shown an increase with the CSA replacement through 10 percent at 28 days of curing. Nevertheless, the relation between compressive strength and weight change of specimens shows a low linear relationship.

Acoustic Emission monitoring of OPC mortars at elevated temperatures in fracture tests

The action of moderate and high temperatures produces the degradation of main physical and mechanical properties of Ordinary Portland Cement (OPC) composites. As an example, from an application point of view and at a structural level, the case of concrete radiation shielding containers in nuclear facilities can be mentioned, which can be severely affected by thermal cracking. In this work, the results of Acoustic Emission (AE) monitoring of mortar prismatic specimens under three-point bending tests are analyzed. Samples are firstly submitted to a heating treatment in an electrical furnace, with maximum target temperatures ranging between 100 to 600 ºC. After the heating process, the prisms were cooled down and finally, mechanically tested, i.e. under residual conditions. The AE signals were continuously recorded during each bending test and its characteristics at different loading stages were explored, scrutinizing variations in AE parameters, such as event rise time, amplitude and energy. Additionally, average frequency (AF) and RA value parameters were employed to assess fracture modes aiming to highlight situations where tension or shear/mixed modes predominate through the test. A comparative analysis of the AE characteristics during loading path and progressive damage is presented.

Influence of ZnO on Antibacterial Properties of Portland Cement

This research project focuses on evaluating the antimicrobial properties of a composite material composed of Portland Cement and Zinc Oxide (ZnO). The study assesses the antibacterial activity of this composite by using Escherichia coli (E. coli) as the test microorganism. Bacterial growth assessment is carried out through the Total Plate Count (TPC) method. The investigation involved varying the concentration of ZnO within the Portland Cement composite, specifically at levels of 0%, 1%, 3%, and 5%. The study primarily centers on generating reactive oxygen species (ROS) by ZnO, and this evaluation was conducted under both UV light exposure and without it. This dual approach allows for a comprehensive examination of ROS activity. Furthermore, the research project involves material characterization using X-ray Diffraction (XRD) to determine the nanoparticle size of ZnO and identify the crystal structures present within the composite material. Additionally, morphological analysis is performed using Scanning Electron Microscopy (SEM) to visualize the structural properties of ZnO embedded within the Portland Cement. SEM analysis is conducted at various magnifications, including 1000x, 2500x, 5000x, and 10,000x, to provide a detailed view of the ZnO's structural properties. In summary, this research project explores the antimicrobial potential of a composite material incorporating Portland Cement and ZnO, focusing on ROS generation and the composite material's structural properties. The findings will contribute to our understanding of the material's suitability for applications in antimicrobial environments.

Influence of ZnO on Antibacterial Properties of Portland Cement

This research project focuses on evaluating the antimicrobial properties of a composite material composed of Portland Cement and Zinc Oxide (ZnO). The study assesses the antibacterial activity of this composite by using Escherichia coli (E. coli) as the test microorganism. Bacterial growth assessment is carried out through the Total Plate Count (TPC) method. The investigation involved varying the concentration of ZnO within the Portland Cement composite, specifically at levels of 0%, 1%, 3%, and 5%. The study primarily centers on generating reactive oxygen species (ROS) by ZnO, and this evaluation was conducted under both UV light exposure and without it. This dual approach allows for a comprehensive examination of ROS activity. Furthermore, the research project involves material characterization using X-ray Diffraction (XRD) to determine the nanoparticle size of ZnO and identify the crystal structures present within the composite material. Additionally, morphological analysis is performed using Scanning Electron Microscopy (SEM) to visualize the structural properties of ZnO embedded within the Portland Cement. SEM analysis is conducted at various magnifications, including 1000x, 2500x, 5000x, and 10,000x, to provide a detailed view of the ZnO's structural properties. In summary, this research project explores the antimicrobial potential of a composite material incorporating Portland Cement and ZnO, focusing on ROS generation and the composite material's structural properties. The findings will contribute to our understanding of the material's suitability for applications in antimicrobial environments.

Study on energy use and carbon emission from manufacturing of OPC and blended cements in India.

The demand for production of cements is ever increasing to meet the infrastructure development globally. The energy and emission factors available for cements in most of the life cycle assessment (LCA) databases may not exactly suit for all the geographical locations. The main challenge in Indian scenario is the absence of database for LCA study. This study attempts to develop the energy and emission factors for the manufacturing of cements in Indian context. In the present study, five different cement manufacturing plants located in north, south, east, west and central zones of India are considered to assess the energy dissipation and carbon dioxide emission involved during the production of ordinary Portland cement (OPC). Most of the data is collected from the field, so that the energy and emission factors determined will be suitable for the zonal study. The study is then extended to assess the energy consumption and carbon dioxide emission for three blended cements, viz. Portland Pozzolan cement (PPC), Portland slag cement (PSC) and composite cement (CC) with permissible known replacement levels of fly ash, granulated blast furnace slag and both fly ash and slag, respectively. The average energy use and carbon emission is found to be on higher side in India by 15.14% and 12.64%, respectively, compared to other countries in manufacturing of cements. An average energy consumption in manufacturing of PPC, PSC and CC is found to be respectively 24.5%, 35.3% and 43.13% less compared to that of OPC. The CO2 emission intensity for OPC is found to vary between 893 and 940kg/tonne of cement from five different zones, and an average of respectively 24.8%, 40.97% and 47.18% lower CO2 emission was observed from PPC, PSC and CC compared to OPC. From the inventory results, CC has proven to be a more sustainable cement with low energy consumption and lower CO2 emission compared to other cements.

Flowability and Cracks Patterns of Lightweight Concrete Subjected to Compression and Tension Loading

AbstractConcrete is one of the most widely used buildings materials in construction. One of the concrete types used is foam concrete which is produced by adding liquid foam (a foam agent) to water in the concrete design mix. The purpose of the foam agent is to stabilize air bubbles during the concrete hardening process. This study aims to analyse the flowability and crack patterns of lightweight concrete subjected to compressive and tensile loadings. A lightweight concrete specimen was made using foam, fine aggregate, and Portland Composite Cement. Foam agent and water are combined in a 3:10 ratio to produce lightweight concrete. There were three different foam volume variations namely 15.7 litres, 25.12 litres, and 37.68 litres. The specimens were prepared using cylinders with dimensions of 10 cm by 20 cm. Flowability testing was carried out when lightweight concrete is still in fresh condition. Cracks in foam concrete were examined after compressive and tensile strength tests were performed at 3, 7, and 28 days of age. The research results show that the fresh lightweight concrete mixture from each mixture is sticky, which could prevent the segregation or bleeding. The crack patterns for the compressive and indirect tensile strength tests were essentially identical; namely parallel to the load direction at the age of 3, 7, and 28 days. The cracks were categorized as columnar crack patterns. It could also be noted that the concrete became more resistant as it ages, as the number of cracks decreased.