Limestone Cement Concrete Research Articles

Field implementation of cellulose nanocrystals (CNC) in concrete pavement test track

ABSTRACT This pilot study aimed to fill the knowledge gap on incorporating cellulose nanocrystals (CNC) in concrete pavements in real-world construction settings. The constructability of CNC concrete was evaluated, and the fresh and hardened properties were fully characterised. A series of concrete slabs were placed using ordinary portland cement concrete (OPC mix), portland limestone cement concrete (PLC mix), and PLC-concrete with CNC at a dosage of 0.10% wt. of cementitious materials (CNC mix). CNC and PLC mix showed no significant differences in consistency, workability, and other fresh properties. The addition of CNC did not show significant changes in cumulative heat over PLC. CNC did not lead to notable changes in compressive and flexural strength, modulus of elasticity, coefficient of thermal expansion (CTE), and electrical resistivity. However, the CNC mix had a notably 9% lower drying shrinkage strain at seven months than the PLC mix. The PLC mix exhibited the lowest water absorption rate, while CNC did not induce significant changes. Overall, this study highlights the constructability of concrete slabs with CNC, with notable contributions of CNC to reducing long-term drying shrinkage.

Impacts of advanced metals recovery on municipal solid waste incineration bottom ash: aggregate characteristics and performance in portland limestone cement concrete

The optimization of alternative materials in concrete production continues to garner considerable attention in order to meet sustainability goals and supplement natural materials. Portland limestone cement (PLC) and municipal solid waste incineration (MSWI) bottom ash (BA) have been proposed separately as green cement and coarse aggregate supplement in low-strength concrete production, creating sustainable products and alternative disposal scenario for a waste material. This study discusses the impact of advanced ash processing techniques on aggregates and presents the performance of concrete incorporating both of these products with PLC for the first time. Two sources of MSWI BA were investigated, one as-produced (TMR) and one processed with novel advanced metals recovery (AMR). The AMR process reduced total Al content in ash compared to TMR (20,500 vs 17,000mg/kg), though not aluminum oxide content, as the AMR process targets metallic aluminum. A composition study on both aggregates supports a reduction in ferrous and non-ferrous metals following the AMR process. All control and test mixes met 28-day compressive strength requirements (17Mpa). Both AMR and TMR MSWI BA-amended concretes yielded compressive strengths below control specimens (no ash) ranging from 17 to 23MPa, with little to no difference observed dependent on MSWI BA processing. The life-cycle discussion supports benefits deriving from supplementing naturally mined materials and recovering ferrous and nonferrous metals with the AMR process.

Investigation of Compressive Strength of Slag-based Geopolymer Concrete Incorporated with Palm Oil Fuel Ash

The paper investigated the compressive strength of ground granulated blast furnace slag-based geopolymer concrete incorporated with palm oil fuel ash compared to portland limestone cement concrete. An appropriate geopolymer mix design was first determined. This mix entailed fine aggregates: coarse aggregates: cementitious material: liquid ratio of 2: 2.5: 1: 0.5, respectively, with 100% replacement of portland cement with ground granulated blast furnace slag (GGBS) incorporated with palm oil fuel ash (POFA). An alkaline solution was used in place of water containing sodium hydroxide and sodium silicate. Following this design, five geopolymer mixes were prepared, each of varying POFA-GGBS ratios of 0:100, 25:75, 50:50, 75:25, and 100:0, and a 14M alkaline solution was used. In addition, a control mix was determined, comprising 100% portland limestone cement (PLC) as the cementitious material and 100% water. Three cubic samples were casted for each geopolymer mix with the control mix, and then the geopolymer mixes were thermally cured for 24 hours. The compressive strength test was conducted on the test samples after ambient curing of 7 days and 28 days, and values for compressive strength (MPa) and failure load (KN) were recorded. Through comparative analysis, it was determined that the most efficient geopolymer mix was mix 2 of GGBS: POFA ratio of 75:25 with 14M alkaline solution. Mix 2 achieved the highest compressive strength of 65.41MPa, approximately 21.99% higher than the strength attained by portland cement concrete samples, measured to be 53.62MPa. Thus, geopolymer concrete can achieve greater strength than portland cement concrete. Keywords: Alkaline solution, Geopolymer concrete, cementitious material, ground granulated blast furnace slag, compressive strength, palm oil fuel ash

Early-stage assessment of drying shrinkage in Portland limestone cement concrete using nonlinear ultrasound

• This paper presents a proof-of-concept evaluation of the durability of OPC and PLC concretes in terms of the microcracking development. • SHG technique is employed to investigate the role of limestone in the dimensional stability under the condition of drying shrinkage. • β , strain, and mass are measured to quantitatively assess the early‐stage microcracking development in both PLC and OPC concretes. • This paper demonstrates the potential of the SHG method for monitoring early-stage damage evolution in both OPC and PLC concretes. Second harmonic generation (SHG), a nonlinear ultrasonic technique, holds great promise for reliable structural health management owing to its nondestructive detection of early-stage damage evolution in cement-based materials. Utilizing the SHG technique, this study focuses on elucidating the contribution of limestone to dimensional stability under drying shrinkage in cement-based materials. Specifically, the acoustic nonlinearity parameter β obtained from the SHG is used, together with uniaxial strain and mass reduction, to characterize the microstructural condition near the surface (∼50 mm) of Portland limestone cement (PLC, Type IL) concrete, which is compared to ordinary Portland cement (OPC, Type I/II) concrete. In both PLC and OPC specimens, β increases remarkably compared with other measured parameters (i.e., change in mass, strain). This demonstrates the sensitivity of this approach to the microstructural modification caused by drying shrinkage, allowing for the discrimination in performance of PLC and OPC.

Cement-based concrete modified with Vitellaria Paradoxa ash: A lifecycle assessment

• EE of PLC-VPA-based concrete reduces with increasing VPA content in the mix. • PLC-VPA-based concrete offers a potential saving on GWP. • PLC-VPA-based concrete provides a potential saving on GTP. • Si of PLC-VPA-based concrete with increasing VPA content. • Ei of PLC-VPA-based concrete reduces with increasing concrete grade strength. Building sustainable concrete requires an increasing demand for technology, innovation, and alternative binders to cement. The building sector is technologically driven toward sustainable construction materials and their relationship with the environment. Thus, this study designed three grades of cement-based concrete strengths (C 25, C 30, and C 40) modified with an alternative binder, shea nutshell ash (Vitellaria Paradoxa Ash, VPA). The binder (VPA) was varied at 0–20 wt% of Portland limestone cement (PLC) cured at 28 days, examining the compressive strength cost attained sustainability. Moreover, the embodied energy (EE), global warming potential (GWP) and global temperature potential (GTP) of the concrete compositions were evaluated using the inventory of carbon and energy (ICE) method within the confine of cradle-to-site. Also, the sustainability index (S i ) and economic index (E i ) of the concrete mixes were assessed. The results revealed that VPA-cement-based concrete yielded a lesser EE, GWP, GTP, S i , and Ec i than the control concrete (Portland limestone cement concrete, PLCC), indicating VPA-cement-based concrete is more sustainable than PLCC. Notwithstanding, an optimum replacement of 15 wt% PLC with VPA is recommended to satisfy all assessments earlier stated for all concrete strength grades. Therefore, these findings can be beneficial in attaining a cleaner built environment and sustainable production. Finally, VPA has proved to be a sustainable building material.

High temperature impact on calcined clay-limestone cement concrete (LC3)

A lot of CO 2 is released into the atmosphere during the manufacturing process of cement, which causes a global warming problem. Calcined clay-limestone cement concrete (LC 3 ) can be used to partially solve this problem. Limestone cement concrete is produced from calcined clay-limestone cement which is an advanced ternary mixed cement formed by the combination of 30 percent low-grade calcined clay, 15 percent limestone powder, and 5 percent gypsum and 50 percent cement clinkers. That means 50 percent of cement clinkers are to be replaced by additional cementitious materials which are beneficial for reducing CO 2 emission at the time of production of cement. In the present study, calcined clay-limestone cement is used to prepared concrete and compare it with concrete using ordinary portland cement (OPC) of grade 53. The physical and chemical characteristics of prepared cement samples were carried out and compared with OPC. M30 grade of concrete was prepared by calcined clay-limestone cement; mechanical properties such as compressive strength (CS) test are carried out on prepared concrete. After the age of 28 days, M30 grade of concrete was exposed to 100 °C, 200 °C, 400 °C, 600 °C, and 800 °C temperature, surface texture, weight loss, compressive strength test were carried on the cubes of size 150 × 150 × 150 mm 3 . The SEM analyses were carried out over 100 °C and 600 °C temperature on OPC and calcined clay-limestone cement concrete. The result shows that the compressive strength reduces with an increase in exposed temperature. The compressive strength decreases after 200 °C and significant losses occur after 400 °C. When the temperature reached 400 °C, noticeable minute cracks started to appear on the surface of the cube specimens.

Effects of Minimum Cementitious Paste Volume and Blended Aggregates on Compressive Strength and Surface Resistivity of Portland Limestone Cement Concrete

AbstractPortland limestone cement (PLC) has been used in all classes of concrete in Florida since 2017. In order to comprehensively use PLC, this study investigates the effects of cementitious past...

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.

Effect of Carbonation Curing on Portland Cement MgSO4 Attack: Laboratory Characterization at 900 Days

AbstractSulfate exposure at low temperatures is known to accelerate chemical deterioration in limestone cement concrete by promoting thaumasite formation. Carbonation curing as an emerging CO2 sequ...

The effects of reduced paste volume in Portland limestone cement concrete

In Portland cement concrete, a high content of cementitious materials can cause early cracking. This study investigated the effects of minimised paste volume in structural concrete made with Portland limestone cement and blended aggregates (BA). The effects of using different types of cement and paste volumes were compared. It was found that concrete made using type IL cement (containing 14% limestone powder) showed comparable performance to concrete made with type I/II cement. Based on the results of laboratory testing and numerical modelling, the performance of concretes with different paste volumes was evaluated. The results showed that the paste volume could be reduced by around 27% without affecting the properties of the concrete. Using the BS technique, the paste volume could be further reduced by 24%. Concrete mixes prepared using the BA technique were found to have better potential performance than the reference concrete. It was concluded that the use of type IL cement and BA can effectively reduce the initial cost and carbon dioxide emissions of structural concrete without loss of performance.

Concrete strength development and sustainability: the limestone constituent cement effect

In this paper, a systematic analysis, evaluation and modelling of the sourced global strength data of concrete where Portland cement (PC) is partially replaced with ground limestone (GLS) is presented. The data – sourced from literature published in English language since 1976, by 250 researchers working at 160 institutions in 43 countries – yielded a matrix of 14 707 data points. The effect of the addition of GLS together with its fineness, concrete design strength, curing duration and water/cement (w/c) ratio are studied. It is shown that concrete strength decreases with the addition of GLS, and at an increasing rate with GLS content. However, this loss in strength of concrete may, to a limited extent, be modified by means of GLS fineness, design strength, curing and the w/c ratio. At a fixed w/c ratio, the GLS content would most likely limit strength development, with the mix unable to develop an equal strength to that of the control PC mix. It is also shown that perceived sustainability benefits would be negated where concrete mixes are designed for specific 28 d strength. This is the case particularly for high-strength PC–limestone cement (PLC) concrete. Notwithstanding this, the use of PLC at higher content than in the corresponding PC can be beneficial with low-strength, S4 slump class or self-compacting concrete, where the filler effect of GLS ensures production of stable concrete mixes free from bleeding and segregation risks and the specified strength is achieved by reducing the w/c ratio of such mixes.

Effects of local metakaolin addition on rheological and mechanical performance of self-compacting limestone cement concrete

Various mineral additions are used in the manufacture of self-compacting concrete (SCC) to reduce the cement content and hence the CO2 emissions and also to enhance the performance of concrete. In this paper, the results of fresh and hardened properties of self-compacting limestone cement mortar (SCLCM) and concrete (SCLCC) with metakaolin (MK) as cement replacement are reported. SCLCM properties investigated include spread flow, V-funnel flow time, yield stress, plastic viscosity and heat evolution. SCLCC fresh properties include slump flow, V-funnel flow time, J-Ring, L-Box and sieve segregation. Compressive strength of the hardened SCLCC was measured at the ages of 1, 3, 7, 28, 90, and 180 days. Moreover, water porosity, water absorption by capillarity and dynamic modulus of elasticity (Ed) tests were conducted. Test results indicated that the produced MK is of sufficient pozzolanic activity and contributes to improve the performances of concrete in particular at later stages. The addition of MK to SCLCM mixes exhibits lower heat evolution, lower yield stress, higher plastic viscosity and higher V-funnel flow time. The addition of MK to SCLCC mixes improves the rheological properties (flowability, passing ability and segregation resistance) as well as the mechanical and durability performance.

Performance of limestone cement concretes in chloride–sulfate environments at low temperature

Portland–limestone cement concretes were stored in two chloride–sulfate solutions, corresponding to exposure classes XS2, XA2 and XA3 specified by the standard BS EN 206:2013, at 5 ± 1°C. Their performance was evaluated in terms of the limestone content (15% or 35% w/w) of the cements used and the partial replacement of limestone cement with natural pozzolana, fly ash, blast-furnace slag or metakaolin. Sulfate attack was monitored through visual inspection of the specimens, mass measurements, compressive strength tests and X-ray diffraction analysis. The penetration of chloride ions was evaluated by determining total (acid-soluble) and free (water-soluble) chloride contents, as well as apparent chloride diffusion coefficients. Limestone cements favoured thaumasite sulfate attack and chloride accumulation in concrete compared to ordinary Portland cement. Mineral admixtures improved the concrete's durability against sulfate attack, inhibited chloride penetration and enhanced chloride binding. Fly ash, metakaolin and blast-furnace slag were more effective than natural pozzolana. Higher sulfate content of storage solutions promoted deterioration, and decreased chloride diffusion coefficients. The results obtained for concretes with mineral admixtures were competitive with those achieved when ordinary Portland cement was used.

Modeling of Hydration, Compressive Strength, and Carbonation of Portland-Limestone Cement (PLC) Concrete.

Limestone is widely used in the construction industry to produce Portland limestone cement (PLC) concrete. Systematic evaluations of hydration kinetics, compressive strength development, and carbonation resistance are crucial for the rational use of limestone. This study presents a hydration-based model for evaluating the influences of limestone on the strength and carbonation of concrete. First, the hydration model analyzes the dilution effect and the nucleation effect of limestone during the hydration of cement. The degree of cement hydration is calculated by considering concrete mixing proportions, binder properties, and curing conditions. Second, by using the gel–space ratio, the compressive strength of PLC concrete is evaluated. The interactions among water-to-binder ratio, limestone replacement ratio, and strength development are highlighted. Third, the carbonate material contents and porosity are calculated from the hydration model and are used as input parameters for the carbonation model. By considering concrete microstructures and environmental conditions, the carbon dioxide diffusivity and carbonation depth of PLC concrete are evaluated. The proposed model has been determined to be valid for concrete with various water-to-binder ratios, limestone contents, and curing periods.

Long term study of mechanical properties, durability and environmental impact of limestone cement concrete

Abstract In this study, properties of limestone cement concrete containing different replacement levels of limestone powder were examined. It includes 0%, 5%, 10%, 15%, 20% and 25% of limestone powder as a partial replacement of cement. Silica fume was added incorporated with limestone powder in some mixes to enhance the concrete properties. Compressive strength, splitting tensile strength and modulus of elasticity were determined. Also, durability of limestone cement concrete with different C 3 A contents was examined. The weight loss, length change and cube compressive strength loss were measured for concrete attacked by 5% sodium sulfate using an accelerated test up to 525 days age. The corrosion resistance was measured through accelerated corrosion test using first crack time, cracking width and steel reinforcement weight loss. Consequently, for short and long term, the use of limestone up to 10% had not a significant reduction in concrete properties. It is not recommended to use blended limestone cement in case of sulfate attack. The use of limestone cement containing up to 25% limestone has insignificant effect on corrosion resistance before cracking.

Impact of organic carbon on hardened properties and durability of limestone cement concrete

Abstract In this paper, the effect of organic carbon in ground limestone on the properties and behavior of Portland limestone cement (PLC) concrete in normal and aggressive medium was studied. Three different sources of limestone with total organic carbon of 0.94, 0.48 and 0.18% were considered, the cement replacement ratios were 0, 10, 15, 20 and 25% by weight and water to binder ratio was 0.55. Mechanical properties, XRD and TGA experiments were conducted to evaluate the effect of the previous variables on hardened properties of concrete and hydration process of cement paste. Corrosion rate and polarization resistance of reinforcing PLC concrete specimens immersed in 5.0% sodium chloride solution for 12 months were measured using potentiodynamic polarization resistance technique. The sulfate resistance of PLC concrete specimens was also investigated. Concrete specimens exposed to wetting and drying cycles in 5% magnesium sulfate solution for 18 months were tested. SEMs of limestone cement paste after magnesium sulfate exposure were performed. The results emphasize the essential role of organic carbon on the properties and behavior of PLC concrete for both normal and aggressive medium especially at high ratios of cement replacement with limestone.

Corrosion behaviour of reinforced steel in concrete with ground limestone partial cement replacement

Corrosion of steel bars embedded in concrete made of Portland cement replaced partially with ground limestone is studied. Three variables are considered: replacement ratios with ground limestone (0, 10, 15, 20 and 25% of cement by weight), level of cement content (300, 350 and 400 kg/m3) and fineness of ground limestone (345, 530 and 720 m2/kg). Reinforced concrete specimens are immersed in a 5% sodium chloride solution by weight up to 9 months. The corrosion rate is measured by potentiodynamic polarisation technique. To explain the corrosion behaviour of steel bar embedded in Portland limestone cement concrete, samples are prepared from the same concrete mixes and tested mechanically and physically. X-ray diffraction and thermogravimetric analyses of limestone cement pastes with similar replacement levels are also conducted. The corrosion rate of steel bars embedded in concrete containing ground limestone (530 m2/kg or more) is found to decrease with increase of cement replacement ratio up to 25% by weight. The corrosion behaviour of steel bars and the resistivity characteristics of Portland limestone cement concrete are also found essentially to depend on the cement content of the concrete. The corrosion behaviour of steel bars in Portland limestone cement concrete, as well as the compressive strength of the concrete, is found to be strongly associated with the fineness of limestone relative to the fineness of cement.

Chloride Diffusion in Limestone Cement Concrete Exposed to Combined Chloride and Sulfate Solutions at Low Temperature

The chloride diffusion in limestone cement concrete exposed to combined chloride and sulfate solutions at low temperature was studied. For this purpose, a normal Portland cement and two Portland limestone cements (15% and 35% w/w limestone content) were used for concrete preparation. The specimens were immersed in two combined chloride-sulfate solutions of different sulfate content, and stored at 5°C. The total and free chloride contents, as well as the chloride diffusion coefficients were determined for each concrete composition. The results show that the total chloride content and free to total chloride ratio are increased with time. The sulfate content of the corrosive solutions has not a clear effect on total chloride content and chloride diffusion coefficient. It seems that the lower sulfate content results, in general, in higher free to total chloride ratio values. The use of limestone in cement results in higher chloride concentrations in concrete and free to total chloride ratio values. In general, these phenomena are intensified for higher limestone content.

Long Term Behaviour of Portland Limestone Cement Concrete Exposed to Combined Chloride and Sulfate Environment. The Effect of Limestone Content and Mineral Admixtures

The long term behaviour of limestone cement concrete, stored in combined chloride and sulfate environment, was studied, taking into consideration the effect of both the limestone content of the cement used and the mineral admixtures addition. Concrete specimens of seven different compositions were prepared. Three of them were made from ordinary Portland cement and from two Portland limestone cements (limestone content: 15% and 35% w/w). The rest four compositions were prepared by substituting a certain amount of the limestone cement (15% w/w limestone content) with natural pozzolana, fly ash, blastfurnace slag or metakaolin. The specimens were immersed in four solutions of various sulfate and chloride contents and stored at 5oC. Visual assessment of the specimens and mass measurements took place up to 55 months. XRD analytical technique was used to identify thaumasite in the deteriorated parts of the specimens. Higher contents of limestone in cement and of sulfates in the storage solutions resulted in more intensive concrete damage. The use of mineral admixtures improved the behaviour of limestone cement concrete. After 24 months of exposure, chlorides delay the deterioration of limestone cement concretes caused by sulfates. After 55 months, the presence of chlorides led to a greater mass loss for them. The specimens containing mineral admixtures showed more intensive deterioration at 24 months when chlorides were present along with sulfates. Their mass seems to not be affected by chlorides. Fly ash was proved as the most efficient material to improve limestone cement concrete's performance, while concrete containing metakaolin suffered from significant damage after 55 months. XRD analysis showed that the damage observed was due to the formation of thaumasite.

Durability performance potential and strength of blended Portland limestone cement concrete

Abstract This paper describes a study on the durability potential and strength of composite Portland-limestone cement (PLC) concrete mixtures blended with ground granulated blast furnace slag (GGBS) and/or fly ash (FA). Their performance was compared against ordinary Portland cement, plain PLC and Portland-slag cement concrete mixtures. Using the South African Durability Index approach, results indicate reductions in the penetrability of the composite PLC blends compared to the other mixtures. The durability indicators are chloride conductivity, gas (oxygen) permeability and water sorptivity. Compressive strength of the composite PLC mixtures containing both GGBS and FA showed competitive performance with the comparative mixtures, but FA blended PLC mixtures had diminished compressive strength values. The paper also presents considerations on the practical implications of using blended PLC concrete mixtures.