Fiber Cement Board Research Articles

Using shredded fibre cement recyclate to produce new innovative fibre cement boards

Abstract The study investigated the effect of the addition of crushed recyclate on the final properties of fibre cement boards. In some fibre cement board production technologies, waste in the form of solid trimmings accounts for up to 7% of total production, which is not an insignificant amount. The research aims to maximise the use of the waste generated and its effective reintegration into the production of new fibre cement boards. In the experimental work, shredded recyclate was used in varying quantities to replace expanded perlite. The results obtained show that the reuse of shredded recyclate has a minimal impact on the observed physical and mechanical properties. A similar trend was found when evaluating the durability tests. The proposed solution for the reuse of recyclate can be considered successful both in terms of production technology and the properties of the fibre cement boards achieved.

Assessment of carbonation as a complementary strategy to increase the durability of Magnesium Oxysulfate (MOS)-based fiber cement boards

Magnesium oxysulfate (MOS)-based fiber cement boards reinforced with lignocellulosic fibers were manufactured using the Hatschek process and cured for 24, 48, and 72 hours before curing in a CO2-rich atmosphere. The boards were rehydrated before the accelerated carbonation process to evaluate changes in carbonation after water addition to the system. The materials showed property changes after accelerated carbonation, which was responsible for an increase of approximately 15 % in the MOR values of the carbonated boards after 48 hours. In contrast, pre-rehydration of the boards increased the Modulus of Rupture (MOR), Limit of Proportionality (LOP), and Modulus of Elasticity (MOE)values of the carbonated materials and favored the production of cementitious composites with specific energy values close to 4.4 kJ/m2. The quantification of mineralized CO2 showed that the rehydrated and carbonated boards after 48 hours presented the highest SCO2(effective) values, which is related to the densification and consequent decrease in voids in the carbonated materials under these conditions. Accelerated aging showed that the carbonated boards had a lower loss of mechanical properties, demonstrating that accelerated carbonation, in addition to increasing mechanical properties, emerges as an alternative to increasing the long-term durability of MOS-based fiber cement boards.

Valorization of magnesium slag and CO2 towards a low carbon fiber reinforced cement board

Pyrometallurgical extraction of magnesium from dolomite ores results in a large amount of magnesium slag discharge and CO2 emission, posing severe environmental hazards. This study introduces a new approach for the simultaneous upcycling of magnesium slag and CO2 by taking advantage of the high carbonation reactivity of magnesium slag. A CO2-solidified magnesium slag-based fiber cement board with high-strength and high-toughness (CHFCB) is developed, using magnesium slag as the binder, CO2 as the activator, and a mix of pulp and PAN fibers as the reinforcement. The optimal CHFCB preparation process was explored by adjusting the fiber ratio, molding pressure, and CO2 curing system, and the mechanisms underlying its strength and toughness were analyzed. The results indicated that with the optimal preparation, CHFCB exhibited a water-saturated flexural strength of nearly 20 MPa and a drying flexural strength of over 25 MPa. The ultimate deflection could be increased by up to 80 % or more during the bending deformation of CHFCB, while the tensile strain could be improved by over 50 % in the tensile fracture process of CHFCB. After 100 freeze-thaw cycles, the water-saturated flexural strength ratio of CHFCB reached 97.2 %, showing excellent durability. The microanalysis revealed that the dense stacking of calcite-type calcium carbonate and the presence of PAN fibers contributed to the high-strength and high-toughness of CHFCB. Additionally, the environmental and economic benefits of CHFCB were assessed, affirming its role as a sustainable building material that promotes energy efficiency and a green economy.

Innovative MOS-based fiber cement boards: Effect of kraft pulp mills waste and curing by accelerated carbonation

The increasing global waste generated by industrial activities poses significant environmental challenges. Eco-waste management emerges as an economically viable solution for converting, valorizing, and repurposing these byproducts, aligning with circular economy principles, and aiming to reduce greenhouse gas emissions. Construction, known for its unsustainability due to high energy consumption, non-renewable resource utilization, waste generation, and greenhouse gas emissions, particularly from cement production, has led to the exploration of alternative materials. Magnesium oxide (MgO)-based cement, an alternative to Ordinary Portland Cement (OPC), has gained attention, leveraging Brazil's prominence as a major magnesite producer. This study explores the valorization of waste from kraft pulp mills of the paper industry, specifically lime sludge (LS) and lime slaker grits (grits), to produce magnesium oxysulfate (MOS)-based fiber cement boards. The effect of accelerated carbonation on cementitious composites produced with formulations containing grits and LS was investigated. Replacing 25% of the limestone with grits showed no noticeable differences in the properties of the boards, and MOR values close to 11.17 MPa were obtained. However, the physical-mechanical performance showed a decrease with the use of LS and higher concentrations of grits, associated with Na2SO4.XH2O formation in the system and ITZ structure formed around the aggregated particle, respectively. Carbonation in a saturated atmosphere led to the carbonation of the 5–1–7 phase, which was related to the decrease in mechanical strength of the boards after the curing process. The thermal decomposition of the Hydrated Magnesium Carbonates (HMCs) formed during accelerated carbonation corroborated with the changes in the physical properties of the composites, demonstrating that the carbonation products are formed within the voids and pores of the material and contribute to the reduction in water absorption of the boards.

Effect of the Rehydration Method on the Physical–Mechanical Properties of CO2-Cured Magnesium-Based Fiber Cement Boards

This article analyzes the effect of the rehydration method on the physical–mechanical properties of accelerated carbonation-cured magnesium-based fiber cement boards. The rehydration process of the boards was analyzed in conjunction with the analysis of the pre-curing time before accelerated carbonation (24, 48, and 72 h before carbonation), resulting in eight different curing parameters used in this investigation. The physical–mechanical performance and microstructural characteristics of magnesium oxysulfate boards before and after carbonation were investigated by water absorption, apparent porosity, and bulk density using the four-point bending test, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. According to the results, the accelerated carbonation process improved the mechanical properties of the boards. The samples that carbonated after 48 h showed a higher modulus of rupture. The rehydration process of the composites before carbonation led to enhancements in the pre-cured boards for 48 and 72 h, demonstrating that carbonation occurred more effectively after water rehydration. The mechanical improvements were associated with the formation of hydration products, which preferentially formed in the pores and voids of the fiber cement matrix. These carbonation products altered the physical properties of the composites, increasing the density of the boards and reducing the void volume. The decomposition of the formed carbonates was confirmed by thermogravimetric analysis, which indicated that the rehydration process favored the carbonation of the composites.

COCONUT FIBER AND PULVERIZED RICE HUSK AS ALTERNATIVE INGREDIENTS IN CONSTRUCTING CEMENT BOARD

Improper disposal of agricultural waste is causing problems in the world today. Since it was seen that using rice husk and coconut fiber can help humans and their environment, this study investigated if coconut fiber and risk husks are potential alternative ingredients in making cement boards. With this, a quantitative experimental design was used to answer the questions this study sought. After the experiment, it was found that rice husk-coconut fiber is not feasible enough in terms of its flexural strength; however, using the rice husk-coconut fiber cement board for interior purposes is recommended. With the limitations of the study, it is also recommended for future researchers to survey rice husk-coconut fiber cement board to use variations with higher water, rice husk, coconut fiber, and cement ratio that can improve the strength and durability of the rice husk-coconut fiber cement board.

Experimental Research on Bearing Capacity of Fiber Cement Board Bottom Formworks and Fastenters of Steel Bars Truss Decks

Experimental Research on Bearing Capacity of Fiber Cement Board Bottom Formworks and Fastenters of Steel Bars Truss Decks

Axial performance of cold-formed steel single-stud wall panels with dissimilar fibre-cement and calcium silicate boards sheathing configuration

In practical applications, it is typical for different types of sheathings (referred to as dissimilar) to be connected at both flanges of the stud (lipped channel-section) in cold-formed steel (CFS) panelised construction (e.g. one-side has interior sheathing and the other exterior sheathing). However, limited studies are available on the axial behaviour of CFS studs with different combinations of sheathings present at both-flanges of a stud. This novel experimental study investigates the structural behaviour of fourteen (14) CFS panels with sheathing on one-side only and different sheathing on both flanges of the wall panel using combinations of seven (7) different sheathing boards [fibre-cement boards (FCB) (8 mm/10 mm/12 mm thick); calcium silicate boards (CSB) (12 mm thick); and heavy duty FCB (6 mm/9 mm/12 mm thick)]. The ultimate axial strength, load-deformation behaviour and failure patterns are the parameters compared. Analytical/semi-analytical design methodologies namely; Rayleigh-Ritz (R-R) method, finite-strip method based on direct strength method (DSM) and differential equation of equilibrium method (DEEM) are validated based on the experiments. Limited studies are available to verify the efficacy of these methods to estimate the axial strength of CFS wall panels with dissimilar sheathing on both flanges. Results establish that DSM may be used efficiently rather than the R-R method and DEEM.

Experimental hysteretic response of cold-formed steel fastened connections sheathed with fiber-cement boards with varied edge distance

Continued development of cold-formed steel (CFS) systems in earthquake-prone areas necessitates study of innovative structural systems and materials. Since cement-based sheathing boards can increase strength and energy dissipation properties – desirable in high seismic zones - fiber-cement boards (FCBs) in particular have become ubiquitous in North American light-framed construction in recent years. This study investigates the effect of three variables, edge distance, stud thickness and fastener type, on the hysteretic performance of 108 CFS-fastener-FCB sheathed specimens. In addition, the impact of over-driven fasteners on cyclic response of the 108 specimens is assessed, and failure modes and tilting of the fasteners are discussed. The tested specimens are designed to simulate a slice of a shear wall. Two studs, one at the top and the other at the bottom, are doubly-sheathed with FCBs, connected via eight fasteners. The specimens are tested cyclically using the FEMA 461 loading protocol, providing extensive experimental data for these connections. Population-level results are analyzed to determine relationships between experimental variables and failure modes. The results of this project will inform national design specifications and establish a comprehensive database of cyclic behavior of CFS-screw-FCB sheathed connections to facilitate the design of the cold formed steel shear walls and diaphragms sheathed with fiber-cement boards.

Sound Transmission Loss in Light Steel Framing Walls With Vermiculite and Recycled-pet Fiber

Due to the demand for multifamily constructions, there is an increasing need for buildings with enhanced acoustic comfort. This study evaluated the acoustic performance of facade walls in the Light Steel Framing (LSF) construction system, using recycled-PET (Polyethylene Terephthalate) fiber and vermiculite board according to ISO 10140:2021 (Acoustics – Laboratory measurement of sound insulation of building elements). Experimental tests on sound transmission loss (STL) were conducted on LSF walls, comprised of two plates (a fiber cement board and an OSB (Oriented Strand Board) separated by an air gap. Four different internal cavity configurations were considered herein: a prototype without any material inside the wall; the second configuration with only recycled-PET fiber inside; the third configuration with solely vermiculite board inside; and the last model with both recycled-PET fiber and vermiculite board inside the wall. The ‘composite’LSF wall with two sound absorbing materials inside, achieved the value of STL equal to 37 dB. It complies with the minimum requirements of the Brazilian Standard NBR 15575-4 (ABNT, 2021) for facades. Furthermore, this study introduces a new approach for LSF walls which considers the introduction of vermiculite boardin between the external boards.

The Study of Carbonyl Emissions and Ozone Removal on Green Recycled Building Materials

Green recycled building materials (GRBMs) have the potential to reduce carbon footprint but with insufficient emission information. The increasing application of GRBMs may affect human health due to potential primary and/or secondary emissions. This study centers on assessing carbonyl emissions and ozone removal on green recycled building materials under ozone exposure circumstances. Tested materials include gypsum board (GB), waterproof gypsum board (WGB), fiber cement board (FCB), and calcium silicate board (CSB). Among all the observed carbonyls, methacrolein and formaldehyde were the only two that could be found on all four recycled building materials. All carbonyl compounds had relatively high emission factors at the beginning of the experiment and decreased to a relatively lower level one month later. Carbonyl emissions were about 33.3%, 38.9%, 42.0%, and 8.0% of their original values for WGB, FCB, CSB, and GB, respectively. The ozone removal efficiencies at the beginning and one month later were 63.26±6.11% and 61.59±5.46% on CSB, 55.74±4.94% and 47.16±7.97% on FCB, 54.59±6.50% and 34.93±6.77% on GB, and 53.63±8.40% and 23.49±6.63% on WGB, respectively. CSB seems to be a healthier recycled building material compared with WGB, GB, and FCB in terms of low carbonyl emissions and high ozone removal efficiency.

Utilization of magnesium slag to prepare CO2 solidified fiber cement board

Magnesium slag is a solid waste produced during industrial magnesium refining. The large amount of magnesium slag produced each year not only causes environmental pollution, but also poses a risk to human health. This paper proposes the use of magnesium slag as a carbonation binder, to produce a new type of CO2 solidified fiber cement board (CSFCB) by accelerated carbonation curing. The mechanical properties, microstructure, durability, and volumetric stability of CSFCB were investigated, and its environmental benefits were evaluated. The results indicate that, under optimal process conditions, CSFCB can attain a water-saturated flexural strength of more than 14 MPa, a carbonation degree higher than 40%, and a water absorption rate as low as 14.9% after 24 h carbonation curing. Phase assemblage and microstructure analysis attribute the high performance mainly due to the voluminous precipitation of calcium carbonate, and the strong bonding of reinforcing pulp fibers with the matrix. This also leads to the improved freeze-thaw resistance and negligible warping deformation. Furthermore, compared to traditional fiber cement board (TFCB), CSFCB exhibits added benefits of carbon absorption and solid waste valorization by the ecologic assessment. The results of the pilot production of CSFCB show that the production and utilization of CSFCB will significantly reduce environmental pollution.

Production of micro-lignocellulosic fibril rubber composites and their application in coated layers of building materials

Novel composite materials were made by combining micro-lignocellulosic fibrils and natural rubber applied as spray coated layers for building materials. The micro-lignocellulosic fibrils were produced based on the mechanical pulping process with jute bast as the raw material. The obtained micro-lignocellulosic fibrils had a good content of water-suspended materials with fibril widths of about 0.1 to 1.0 µm and fibril length of about 100 to 150 µm. The composites were produced using natural rubber mixed with the micro-lignocellulosic fibrils at 0, 5, and 10 parts per hundred of rubber, vulcanizing sulfur, and activated zinc oxide. The fibril-rubber suspension was formed in the composite sheets with a thickness of 0.5 to 1.5 mm using a spray coating technique and was oven-dried at 100 °C. The rubber composite had a homogenous fibril distribution in the rubber composite matrix, with good bonding between the fibrils and the rubber polymers. The fibrils contributed to the strength reinforcement of the rubber composite layers. The application of the micro-lignocellulosic fibril rubber composites coated onto industrial fiber cement boards enhanced the thermal insulation properties, which had a lower degree of thermal conductivity and heat diffusivity and enhanced the toughness and waterproofing of the fiber cement boards.

Experimental and theoretical research on flexural performance of truss reinforced concrete two-way composite slab with prefabricated baseplate

This paper presents experimental and theoretical research on a novel truss reinforced composite concrete two-way slab using full-scale testing. In contrast to conventional composite slabs, the precast concrete layer with a thickness greater than 60 mm is replaced by a high toughness prefabricated inorganic baseplate with a thickness of 12 mm. The baseplate options include glass fiber and magnesium cement board, as well as fiber cement board. Four full-scale two-way slabs were subjected to eight points simulated uniform vertical loads, comprising one conventional truss reinforced concrete two-way slab (RCS) and three truss reinforced concrete composite two-way slabs with prefabricated baseplates (RCSB). The test results indicate that the failure mode of the truss reinforced concrete composite two-way slab with baseplate is similar to that of a common truss reinforced concrete two-way slab. However, a rectangular yielding region appears at the central part, instead of a single yielding line. The cracking load and ultimate load are increased due to the effect of prefabricated baseplate. Moreover, the beneficial effect of glass fiber and magnesium cement board is superior to that of fiber cement board. Finally, the calculation methods for determining the cracking load and ultimate bearing capacity of truss reinforced concrete composite two-way slabs with baseplates were improved, and the calculated results are in good agreement with experimental data.

Novel surface functionalization of cellulose fibers with polyurethane prepolymers in fiber cement composites: Impact on final properties and potential benefits for the production process

The objective of this research was to perform a deep exploration of cellulose polyurethane (PU) fibers used in fiber cement boards for usage in building applications. Grafting treatment was performed on cellulose fibers with PU-pre-polymers, through a synthesis method using propylene carbonate solvent medium, followed by a cleaning step. Fiber cement boards were prepared thorough cement and limestone dispersion followed by a dewatering process, to roughly mimic the Hatschek production process. The experiments confirmed that grafted cellulose fibers can present lower water absorption (∼10 %) and greater fiber preservation, when embedded in alkaline matrix. Although the mechanical performance of fiber cement composites prepared with cellulose-PU fibers were not appreciably different, superior ability to drain water from the green cement sheet was demonstrated, which can provide great benefits during the production process. It’s worth mentioning that cellulose fiber is added in the air cured fiber cement formulation as a process aid agent to retain fine aggregates, and mechanical reinforcement is mainly carried out by the synthetic fibers. From the fiber cement production perspective, the reduced water retention showed in the green sheet can be beneficial in different production processes, e.g. the Hatschek or flow-on, in two ways: First, by possibly reducing the number of stops, as a lighter green sheet would be less prone to drop from the machine, and second, due to lower vacuum applied, possibly avoiding segregation and producing more homogeneous boards.

Use of Alternative Raw Materials for the Production of Fiber Cement Products

The paper deals with the production of fiber cement and the use of alternative raw materials in its production. The paper describes the basic technologies used for the production of fiber cement with a description of their advantages and disadvantages for the given type of product. The paper also describes the most commonly used types of fillers and their impact on the final fiber cement products. The paper also describes selected alternative raw materials used for the production of fiber cement and their impact on the final products. The paper describes the possible use of waste dust from facade fiber cement boards in the production of corrugated sheets. Trial recipes were designed with partial replacement of original raw materials with waste dust. The fiber-cement corrugated sheets were produced with using Hatchesk technology. Mainly was investigated the influence of the addition of waste dust on the strength characteristics and the volume weight of the final products. The produced sheets were tested according to EN 494+A1: 2016 Fibre-cement profiled sheets and fittings - Product specification and test methods. The tested samples with waste dust reached comparable results like sheets produced according to standard recipe. No negative effect was proven of the addition of waste dust on the strength characteristics of final products.

Analisis Risiko Kecelakaan Kerja pada De-Pilling Machine After Autoclave Menggunakan Metode JSA dan Pengontrolan Risiko Menggunakan Metode HIRARC pada PT.XXX

PT XXX is one of the companies engaged in goods, more precisely the manufacture of fiber cement boards and wave boards. Every product that will be marketed will be packaged where the packaging is done in the De-pilling Machine after Autoclave (DMA) area. Not all DMA machines run automatically and are run by one person, there are still DMA machines that run manually, which still require the help of human labor, because when working in manual DMA the risk is great and is done by several people, so in this area risk analysis, risk identification, risk level determination, risk control and handling are needed as an effort to improve Occupational Health and Safety (K3). The method to be used is the Job Safety Analysis (JSA) method because this method focuses on identifying hazards in the work, then the hazards will be controlled by the Hazard Identification And Risk Control (HIRARC) method. From the analysis using the JSA method, 8 jobs were found to be at risk with an average risk level of Medium - High so risk control is needed for these 8 jobs. The work will be analyzed for hazards and controlled risks, the goal is to know the magnitude of the risk of work and prioritize controlling which jobs have the most significant risk and if possible, replace machines that are still manual with automatic machines to be more efficient, reduce risk and do not require many people.

Influence of Fire Exposition of Fibre-Cement Boards on Their Microstructure.

The diagnostics of materials, elements and structures after fire exposure are very complicated. Researchers carrying out such diagnostics encounter difficulties at the very beginning, e.g., how to map fire conditions. In this publication, the authors focused on the analysis of the fibre-cement composite used as facade cladding. The fibre-cement boards are construction products used in civil engineering. The fibre-cement boards are characterised by two phases: the matrix phase and the dispersed phase. The analysis of fibre-cement composite was performed using non-destructive methods. The use of non-destructive methods in the future will allow for the analysis of facades after fires without the need to obtain large elements, which will significantly reduce costs while increasing safety. The aim of the work was to determine internal changes in the microstructure of fibre-cement boards after exposure to fire. The degraded samples were compared with reference samples in the evaluation of the microstructure. An analysis was performed using a scanning electron microscope, images of backscattered electrons (BSE) and maps obtained using Energy Dispersive X-ray Spectroscopy (EDX), which allowed conclusions to be drawn. The observed changes were presented in the form of photos showing changes in the composition of the plates, and they were commented on. It should be noted that fire temperatures act destructively, and a number of changes can be observed in the microstructure. The results of the work indicate that, in the future, the use of non-destructive methods will make it possible to assess the degree of degradation of the façade after a fire.

Experimental and Numerical Investigation of the Mechanical Properties of a Fiber-Reinforced Geopolymer Mortar Blast Resistant Panel.

Geopolymer materials have excellent properties such as high strength, low thermal conductivity, fire resistance, acid and alkali resistance, and low carbon emissions. They can be used as protective engineering materials in places with explosion risks. At present, the common composite blast resistant panel is in the form of a sandwich: the outer layer isgalvanized steel plate, and fiber cement board or calcium carbonate board is used as the inner layer material, as these boards have the advantages of easy installation, good fire resistance, and explosion resistance. This study investigates the effect of adding different types of fibers to geopolymer mortar on the mortar's basic mechanical properties, such as compression strength, bending strength, and impact resistance. The explosive resistance of the fiber-reinforced geopolymer mortar blast resistant panels was evaluated through free-air explosion. In this paper, experimental procedures and numerical simulation have been performed to study the failure modes, maximum deflection, and dynamic response of the fiber-reinforced geopolymer mortar blast resistant panel under free-air explosion. The research results can provide a reference for the design and production of blast resistant panels.

Behavior of a Composite Steel Decking and Boarding System in Fire Based on Large-Scale Experimental Testing and Numerical Modelling

This paper presents experimental and numerical results of an investigation into the thermal and structural behaviour of an innovative modular structural steel system, which includes cellular beams, that was tested in a 1-h standard fire scenario while loaded. The modular system consists of a 5.66 × 3.8 m rectangular steel frame, with a profiled steel sandwich decking (SD) system attached, which comprises of (a) profiled steel decking, (b) fibre cement, and (c) calcium silicate boards and strips. The SD system is suspended from the underside of the horizontal structural members to provide inherent fire protection to the steel beams from the bottom and acts as the load-bearing component of the flooring. The purpose of the experiment was to determine the fire resistance of the structural system, whilst under load, which is primarily based on the fire resistance of the SD system. Temperature data for the SD system was collected during the experiment and used to validate a numerical finite element analysis model. This study shows that the SD system was able to achieve a fire resistance rating of 57 min in the experiment which was governed by insulation resistance. A lower fire resistance rating is estimated based on numerical models. Structural resistance was maintained throughout the test. During preliminary testing structural collapse was observed in a separate experiment which highlights how the system is sensitive to damage to the ceiling boards. Numerical results highlight that thermal bowing and movement may result in changes in thermal interactions between adjacent elements. This paper provides novel large-scale experimental data on a loaded flooring system in fire.