Siliceous Concrete Research Articles

Frost Resistance of Silicate Bricks

The article presents the results of a research frost resistance of silicate bricks one of the Russian factories produced in different periods. The change in appearance, weight and strength of silicate bricks during alternate freezing-thawing was evaluated. It has been established that silicate bricks, can meet high frost resistance grades F150-200, in terms of appearance, while the reduction in compressive strength does not exceed 9%. Some increase in brick strength at the initial stage of testing was noted, which is probably explained by the processes of carbonization of free calcium hydroxide and high-basic calcium hydrosilicates, accompanied by their recrystallization into low-basic ones, which is confirmed by the results of differential-thermal and X-ray phase analysis. It is concluded that the frost resistance of silicate bricks is decisively influenced by the mineralogical composition of the cementitious bond. High strength and frost resistance of silicate concrete is provided by the simultaneous presence of low-basic calcium hydrosilicates and α-C2S hydrate in the composition of the new formations. The condition for the formation of such composition of neoplasms is excessive content of lime in the composition of the raw material mixture.

Concrete Highway Crack Detection Based on Visible Light and Infrared Silicate Spectrum Image Fusion.

Cracks provide the earliest and most immediate visual response to structural deterioration of asphalt pavements. Most of the current methods for crack detection are based on visible light sensors and convolutional neural networks. However, such an approach obviously limits the detection to daytime and good lighting conditions. Therefore, this paper proposes a crack detection technique cross-modal feature alignment of YOLOV5 based on visible and infrared images. The infrared spectrum characteristics of silicate concrete can be an important supplement. The adaptive illumination-aware weight generation module is introduced to compute illumination probability to guide the training of the fusion network. In order to alleviate the problem of weak alignment of the multi-scale feature map, the FA-BIFPN feature pyramid module is proposed. The parallel structure of a dual backbone network takes 40% less time to train than a single backbone network. As determined through validation on FLIR, LLVIP, and VEDAI bimodal datasets, the fused images have more stable performance compared to the visible images. In addition, the detector proposed in this paper surpasses the current advanced YOLOV5 unimodal detector and CFT cross-modal fusion module. In the publicly available bimodal road crack dataset, our method is able to detect cracks of 5 pixels with 98.3% accuracy under weak illumination.

Parametric study of molten core concrete interaction and assessment of corium coolability in the light of MCCI experiments

Molten Corium Concrete Interaction (MCCI) is an important phenomenon observed in the late phase of reactor severe accidents. A realistic analysis of MCCI can save cost and efforts to mitigate severe accidents. The heat transfer mechanisms in MCCI, such as melt eruption and water ingression, are the primary focus of current research owing to complications in their quantification and replication in severe accident analysis codes. This study investigated MCCI using top flooding strategy with MELCOR 2.2 code for two concrete types, and three experiments that were conducted under (OECD/MCCI-1 program). The results demonstrated that the ablation process terminated in the case of Limestone Common Sand (LCS) concrete. In the simulation of siliceous (SIL) concrete, the maximum and average melt front locations confirmed the asymmetrical ablation progression. The LCS concrete showed a smaller axial ablation front in this study; however, the comparison with the concrete ablation volume (0.21 m3) showed an exact match, and the difference between the experimental and predicted ablated mass of concrete was only 0.61%. The quantitative comparison between the prediction of the present study, CORQUENCH code, and experimental results is provided. The parametric values of MCCI phenomenon are also predicated and model improvement for MELCOR 2.2 code are discussed as well.

Strengthening mechanism of polyvinyl alcohol fibers on mechanical properties of geopolymer concrete subjected to a wet-hot-salt environment

Concrete materials are subjected to a complex coupled environment of temperature, humidity, and salt ions when in a coastal area during the summer. Geopolymer concrete (GPC), as one of the best alternatives to ordinary silicate concrete, was explored in this study to investigate its mechanical damage under wet-hot-salt environment, and to understand the strengthening mechanism of its mechanical properties by polyvinyl alcohol fibers (PF), which are crucial for the application of GPC in coastal engineering. To achieve this, a series of experiments were conducted to investigate the effect of wet-hot-salt coupled environment and PF content on the mechanical properties of fiber-reinforced geopolymer concrete containing nano-SiO2 (PF-GPC). In the experimental design, a coupled environment of 45 °C temperature, 100% humidity, and 5% NaCl solution content was firstly established for simulation acceleration test by an environmental simulation test chamber. Then different PF volume contents (from 0% to 0.8%) were considered for the cube compressive strength test, split tensile test, elastic modulus test and impact test. The results indicated that the wet-hot-salt environment significantly weakened the mechanical properties of GPC specimens, while the addition of appropriate content of PF effectively mitigated the degradation caused by the wet-hot-salt environment. The compressive strength, splitting tensile strength and elastic modulus of PF-GPC reached their maximum value at a PF content of 0.6%. Particularly, the addition of PF significantly improved the impact resistance of PF-GPC in wet-hot-salt coupled environment, with the highest impact resistance indices observed at a PF content of 0.4%. Moreover, the correlation between the elastic modulus and compressive strength of PF-GPC in wet-hot-salt environment was established by using the power function equation. And based on the applicability of the two-parameter Weibull distribution in the impact life model, an impact damage evolution equation of PF-GPC was established and validated under the wet-hot-salt conditions, which can provide valuable guidance for the design of GPC structures under different damage probabilities. The findings of this study indicated that PF-GPC can be applied in the wet-hot-salt environment, which is important for the low-carbon sustainable development of building materials.

Analysis of Carbon Storage Potential of CO2 Foamed Concrete

The technology of carbon capture, utilization, and storage (CCUS) is an important component of carbon neutral technology systems. To confirm the carbon storage potential of CO2 foamed concrete (CFC), this study addressed the principle of carbon storage in CFC materials. It is apparent that carbon storage of CFC materials includes carbon fixation in concrete skeletons and carbon storage in CFC bubbles. The carbon fixation of CFC skeletons is realized by CO2 mineralization. As the concrete skeleton in CFC is in the CO2 atmosphere, the carbonation of CFC materials or CO2 mineralization is more complete. Research shows that the carbonation rate of CFC materials can reach almost 30% after acidification, foaming with high CO2 pressure and curing in the atmosphere. The carbonation rate is higher than the rate in concrete curing with CO2. A mathematical model was established to calculate carbon fixation capacity in CFC materials, and the carbon fixation and storage capacity in CFC material were estimated. The results showed that more than 99% carbon storage of CFC was realized by the chemical carbonization of the concrete skeleton. Comparatively, the potential of carbon storage in the bubble of CFC was small. In this study, carbon storage capacity was divided into three categories, i.e., theoretical maximum capacity, relative reliable capacity, and expected capacity or potential. The carbonation rate for theoretical maximum capacity was 100%, when all the concrete was considered to be carbonated. As the carbonation rate of concrete during the whole life cycle is approximately 55% all over the world, 50% was set as the carbonation rate for relative reliable capacity calculation. If at high temperatures, CO2 curing with high pressure or accessory ingredients applied to silicate concrete can improve carbonation rate to be over 80%, when the carbon storage capacity is considered to be expected capacity or potential. In 2017-2021, the theoretical maximum capacity of carbon storage was 3.623×109 t CO2 in China, with 7.25×108 t·a-1. The relative reliable capacity was 3.75×108 t·a-1, and the expected capacity was 5.80×108 t·a-1. If the carbonation rate was 30%, the carbon storage of concrete produced annually in China during the whole life cycle reached 2.18×108 t, which was more than the carbon sink of Daxing'anling forest for one year. In coal electricity integrated mining areas and large thermal, metallurgical, cement chemical, and other high-energy consuming enterprises, CFC has a good prospect of development to promote the recycling of solid waste and waste gas. Meanwhile, it is pointed out that the stability of CFC before solidification is a technical problem to be solved in the next step.

Effect of Fiber Dosage On Mechanical Properties Of Geopolymer Mortar Under The Coupling Of Sulfate Erosion And Dry-Wet Alternation

Coastal buildings are susceptible to long-term sulfate erosion and alternating wet-dry cycles, leading to rapid degradation in mechanical properties and durability. Therefore, there is an urgent need to find a construction material that is superior to ordinary silicate concrete. Geopolymer concrete, an innovative environmentally-friendly material, offers advantages like early strength, fire resistance, and durability. Research reveals that even after sulfate erosion, geopolymer concrete outperforms regular silicate concrete in terms of mechanical properties and durability. However, geopolymer concrete suffers from high brittleness. A remedy is found in the incorporation of fibers, which substantially enhances its mechanical properties and durability. This study investigates the influence of carbon fibers and polypropylene fibers on the mechanical traits of metakaolin-geopolymer mortar, exposed to sulfate action and wet-dry cycles for 60 repetitions. Results indicate that the addition of 0.6% carbon fibers yields the highest compressive strength, while a 1:1 combination of carbon and polypropylene fibers produces peak flexural strength. Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) confirm uniform fiber distribution within the mortar, reinforcing material bonds and retarding crack propagation. Consequently, mechanical properties and durability are improved.

Study on Shrinkage in Alkali-Activated Slag-Fly Ash Cementitious Materials.

Traditional silicate cement materials produce a large amount of CO2 during production, making it urgent to seek alternatives. Alkali-activated slag cement is a good substitute, as its production process has low carbon emissions and energy consumption, and it can comprehensively utilize various types of industrial waste residue while possessing superior physical and chemical properties. However, the shrinkage of alkali-activated concrete can be larger than that of traditional silicate concrete. To address this issue, the present study utilized slag powder as the raw material, sodium silicate (water glass) as the alkaline activator, and incorporated fly ash and fine sand to study the dry shrinkage and autogenous shrinkage values of alkali cementitious material under different content. Furthermore, combined with the change trend of pore structure, the impact of their content on the drying shrinkage and autogenous shrinkage of alkali-activated slag cement was discussed. Based on the author's previous research, it was found that by sacrificing a certain mechanical strength, adding fly ash and fine sand can effectively reduce the drying shrinkage and autogenous shrinkage values of alkali-activated slag cement. The higher the content, the greater the strength loss of the material and the lower the shrinkage value. When the fly ash content was 60%, the drying shrinkage and autogenous shrinkage of the alkali-activated slag cement mortar specimens decreased by about 30% and 24%, respectively. When the fine sand content was 40%, the drying shrinkage and autogenous shrinkage of the alkali-activated slag cement mortar specimens decreased by about 14% and 4%, respectively.

Numerical study of aggregate effects on the strength of light concrete

The article represents the results of lightweight concrete’s composition designing by numerical methods. The study is aimed at finding rational aggregate particles packing that provides the highest mechanical characteristics of the composite material. Numerical simulation uses the finite element method. To simplify a calculation scheme, the study was carried out in a flat format. Models with regular aggregate particles of spherical and cylindrical shape have been investigated. The advantage of a two-component model built on the fractal principle of a triangle and containing up to 70% of aggregate particles has been proven. The model of aggregate distribution according to the type of an equilateral triangle provides minimal stresses and deformations inside the composite material. To ensure the mechanical resistance of the composite material, the rounded shape of granules is preferable compared to quasi-cylindrical particles. Under a regular multi-row distribution of rounded granules, the model containing particles with diameter from 6 to 8 mm is characterized by a minimum concentration of normal and shear stresses. The results of numerical simulation are consistent with experimental studies of lightweight alkaline silicate concrete based on porous granular aggregate.

The soft-sediment deformation structures and the siliceous concretion presence as indicators of the depositional processes during Middle Paleocene to Middle Eocene in the Apulian Platform Margins in Kefalonia Island, Greece

Kefalonia Island is situated in western Greece and geologically corresponds to the Apulian Platform Margins (APM), with the Apulian Platform lying to the west and the Ionian Basin to the east. The studied deposits, with a thickness up to 164.5, extend along the 650 m long Agia Efimia bay, ranging from the Middle Paleocene (Selandian) to the uppermost Eocene (Priabonian), during the latest part of the rift stage. Fieldwork measurements of soft-sediment deformation structures (SSDS), paleocurrent directions, the size and abundance of siliceous concretions (SC) and siliceous beds (SB), and shale horizons were correlated with the age of selected samples, and thus, the relation of the tectonic regime with the depositional conditions was presented. As SSDS could represent an indicator of tectonic activity and instability of the basin floor instability, the size and the abundance of the SSDS whereas used to identify the parameters that produced the basin floor instability like the intensity of tectonic activity. The studied section, with a general NE-SW orientation, was subdivided into five (5) different units. The changes of these units in paleocurrent directions, the size, the abundance, and the thickness of SSDS, SC, and SB and the presence of shale horizons in the upper unit, characterize a gradual change of the depositional conditions in the APM, from the Upper Paleocene (Selandian) to the Upper Eocene (Priabonian). The factor that influenced the abovementioned changes was related with the presence and the activity of normal faults that produced instability of the basin floor. Therefore, a reduction in tectonic activity from the Paleocene to the Eocene is suggested.

Life cycle assessment of material footprint in recycling: A case of concrete recycling

Meeting the current demand for concrete requires not only mining tons of gravel and sand, but also burning large amounts of fossil fuel resources in cement kilning. Consequently, concrete recycling is crucial to achieving a material-efficient society, especially with the application of various categories of concrete and the goal of phasing out fossil fuels. A comparative life cycle assessment (LCA) is used to assess the engineering material footprint (EMF) and the fossil fuel material footprint (FMF) in closed-loop recycling of three types of concrete: siliceous concrete, limestone concrete, and lightweight aggregate concrete. This study aims to investigate the impact of (i) concrete categories, (ii) methods to model recycling, and (iii) using renewable energy sources on the material footprint in concrete recycling. The results highlight that the concrete recycling system can reduce 99% of the EMF and 66–93% of the FMF compared with the baseline system, in which concrete waste is landfilled. All three recycling modeling approaches indicate that concrete recycling can considerably reduce EMF and FMF compared with the baseline system, primarily resulting from the displacement of virgin raw materials. Using alternative diesels is more sensitive than adopting renewable electricity in reduction of the FMF in concrete recycling. Replacing diesel with electrolysis- and coal-based synthetic diesel for concrete recycling could even increase the FMF, while using biodiesel made from rapeseed and wood-based synthetic diesel can reduce 47–51% and 84–89% of the FMF, respectively, compared to the virgin diesel-based recycling system. Finally, we discussed the multifunctionality and rebound effects of recycling, and double-counting risk in material and energy accounting.

Residual compressive strength of concrete after exposure to high temperatures: A review and probabilistic models

The mechanical properties of concrete degrade after exposure to high temperatures during a fire event. Proper assessment of damage, determination of the remaining capacity of the structure, and recommendations for repair actions require the quantification of the reduction in the compressive strength of concrete after fire. This paper collects and analyzes the existing data on residual compressive strength of normal strength concrete in the literature. The analyses aim to identify the influential attributes that could be used to reduce scatter in the data. Parameters related to aggregate type, concrete mix, and testing protocol are studied. Subsets of the dataset for concrete with siliceous and calcareous aggregates are created. Data for siliceous concrete is further categorized based on the retaining time of the maximum temperature during the test. The subsets are used to propose probabilistic models for the residual compressive strength of concrete with siliceous and calcareous aggregates. The models follow the Weibull distribution and are continuous functions that can be implemented in analytical and computational frameworks. The medians of the proposed model and data are close to the Eurocode reduction factors for the siliceous concrete but fall below the Eurocode reduction factors for concrete with calcareous aggregate.

Concrete/Glass Construction and Demolition Waste (CDW) Synergies in Ternary Eco-Cement-Paste Mineralogy.

The study described sought further understanding of the synergies in a mix of CDW pozzolans, containing (calcareous and siliceous) concrete and glass waste, used to prepare ternary eco-cement paste bearing 7% of the binary blend at concrete/glass ratios of 2:1 and 1:2. The mineralogical phases in the 2-day, 28-day, and 90-day cement matrices were identified and monitored using XRF, XRD-Rietveld, SEM-EDX, FT-IR, and NMR. The findings showed that changes in the reaction kinetics in the ternary blended pastes relative to OPC pastes depended on the nature of the recycled concrete and the glass content. Adding the binary mix bearing calcareous concrete (at a ratio of 2:1) favoured ettringite, portlandite, and amorphous phase formation, whilst the blends with siliceous concrete favoured C-S-H gel formation. Monocarboaluminate was detected in the 90-day siliceous concrete and glass pastes in amounts similar to those found in the reference OPC paste.

Effect of Temperature on Properties of Concrete in Stirring Process

Taking composite silicate concrete as the research object, the double horizontal shaft mixing method is used to mix concrete. The setting time, strength and workability tests are carried out to study the influence of temperature on the mechanical properties of concrete in the ordinary mixing process. The results show that the temperature has great influence on the setting time, compressive strength and splitting strength of concrete. Reasonable control of cement temperature has important guiding significance and theoretical basis in practical construction application.

Structural and durability properties for magnesia alumina silicate concrete

This paper reports on the fresh, structural and durability properties of a Magnesia-Metakaolin (MgO-Mk) based concrete compared with a conventional Portland cement (PC) concrete. Metakaolin, representing the family of aluminosilicate (Al2SiO3) including low-kaolinitic clays, provides a viable option for use in the M−S−H and M−A−S−H binder system. Two representative cementitious formulations of MgO-Mk cement at a single MgO/clay mass ratio with 100% and 70% Al2SiO3 content were used in the study. In addition to the basic properties of concrete such as strength and density, this paper also presents the result of comprehensive tests undertaken to evaluate the elastic properties and bond performance of the M−S−H concrete using both steel and basalt reinforcing. The results of the current study demonstrate the properties of MgO-Mk-based M−S−H concrete to be comparable with, if not superior to, those of its PC counterpart.

Review on Application of Rice Husk Ash Based Concrete Composite and Preparation Conditions of Rice Husk Ash

Within the past few decades, fabricating 1 ton of standard cement (OPC) will transmit about 1 ton of carbon dioxide. With the increase of demand for cement production, the global carbon dioxide emission has increased by 8%, resulting in huge ecological problems. The continuous development of construction and cement industry has aggravated air pollution and human health damage. Therefore, environmentalists and governments at home and abroad call for the use of other environmentally friendly Supplementary Cementitious Materials to strictly control the carbon dioxide emission rate. Rice husk, as the biggest by-product in rice generation, has been ignored for a long time, and the way of successful utilization of rice husk has not been found. Subsequently, renewable cement based on rice husk cinder (RHA) can be made. This paper analyzes the application prospect of RHA in ordinary silicate concrete and the influence of RHA preparation conditions on RHA, hoping to provide reference for the application of RHA in ordinary silicate concrete.

Experimental study on molten corium-concrete interaction with simulant metal and oxide

Under hypothetical Reactor Pressure Vessel (RPV) failure accidents in Light Water Reactor (LWR), Molten Corium-Concrete Interaction (MCCI) will cause erosion of cavity concrete, possibly resulting in containment failure due to basemat penetration and overpressure. The CINA (Corium-Concrete Interaction Apparatus) experiment was conducted to investigate the MCCI of metallic and oxidic corium with siliceous concrete. Simulant melt material metallic iron and oxidic alumina generated by exothermic thermite chemical reaction was used to investigate the two-dimensional erosion of a cylindrical crucible in CINA experiment. The crucible was fabricated from siliceous concrete with an inner diameter of 300 mm and a height of 500 mm containing reinforcement (rebars). Decay heat in the melt was simulated by subsequent sustained addition of thermite. During the experiment, the melt temperature was monitored by two thermocouples and a two-color optical endurance pyrometer. Besides, the phenomenon that appeared on the melt surface was recorded by the video camera placed above the crucible and the formation process of the crust anchoring was observed. After the experiment, the crucible was split in half by a wire saw to accurately measure the ablation depth. Axial-radial ablation depths were 25 mm and 13 mm, respectively. Current findings contribute to the further understanding of MCCI mechanisms and the optimization of MCCI mitigation strategies.

Comparison between Siliceous Concretions from the Ionian Basin and the Apulian Platform Margins (Pre-Apulian Zone), Western Greece: Implication of Differential Diagenesis on Nodules Evolution

Siliceous concretions (nodules), from two different geological settings—the Apulian platform margins in Kefalonia island, and the Ionian Basin in Ithaca, Atokos, and Kastos islands—have been studied both in the field and in the laboratory. Nodule cuttings are mainly characterized by the development of a core, around which a ring (rim) has been formed. Mineralogical study, using X-ray powder diffraction (XRPD) analysis, showed that the rim is usually richer in moganite than the core. Homogeneous concretions, without discernible inner core and outer ring, were observed generally in both settings. Mineralogical analysis of the selected siliceous concretions from Kefalonia island showed the presence mostly of quartz and moganite, while calcite either was absent or participated in a few samples in minor/trace abundances. Moganite was generally abundant in all the samples from Kefalonia island. Concretions from the Ionian Basin showed a variation in the quartz, moganite, and calcite contents. Mineralogical differences were recognized both between the different studied geodynamic settings and internally in the same setting, but with different stages of development. The above-mentioned differential diagenesis on nodules evolution could be related to the presence and/or abundance of stylolites, later fluid flows, restrictions from one area to another due to synchronous fault activity, and the composition of substances dissolved in fluids. Moreover, the development of concretions produced secondary fractures in the surrounding area of the nodule-bearing rocks.

Lithostratigraphic definition of the Anisian carbonate-ramp deposit of the Annaberg Formation (Middle Triassic, Northern Calcareous Alps, Austria)

Concerning the Middle Triassic stratigraphic succession of the Northern Calcareous Alps (NCA), a modern, litho- and biostratigraphic oriented evaluation of the early- and middle Anisian Annaberg Formation is presented. Due to the fact, that Middle Triassic formations are characterized by a wide distribution within the NCA, any lithostratigraphic definitions of these formations would be of great benefit for mapping geologists, engineers and hydrogeologists. The lithostratigraphic term Annaberg Formation may substitute former designations like “Alpiner Muschelkalk”, “Anisian Limestone and Dolomite” or, partly, “Gutenstein Limestone”. It is exclusively of Anisian age and earlier then the Steinalm and Reifling Formation. Mainly based on microfacies data and lithological data, we define the Annaberg Formation (former: Annaberg Limestone) as one of the most significant Middle Triassic lithostratigraphic units within the NCA. After a detailed description of the type area, findings gained in other areas of the NCA are incorporated to obtain the largest possible overview about the lithological variability and constituents of the Annaberg Formation. As a result, we can describe the Annaberg Formation as mainly organic-rich, medium bedded wackestone, containing remnants of crinoids, little bivalves and gastropods. Typically, fossil-rich layers with accumulations of bivalves and crinoids can often be observed within the Annaberg Formation. In contrast to the Gutenstein Formation no siliceous concretions or fossils (like radiolarians) appear and the fauna is in the main shallow marine. The rock-colour varies from dark- to medium-grey and the bench thicknesses are greater than within the Gutenstein Formation sensu stricto. The fossil content is also larger than in the essentially anaerobe Gutenstein Formation. With respect to the Virgloria Formation the Annaberg Formation is rather planar bedded, not so rich in bioturbation-structures and poor in silica and clay. Hence, the depositional environment of the Annaberg Formation can be described as a restricted carbonate ramp succession, with only minor water movement and separated from the open sea by a shoal with crinoid and brachiopod meadows. Breccias may be an indication for collapse-structures and slumping. In addition, knife-cavity structures (“Messerstichkalke”) indicate an occasional hypersaline environment with precipitation of evaporite-minerals like gypsum. Fossil-rich layers with accumulations of molluscs and crinoids may indicate short-term storm affected sedimentation.

STRENGTH OF ANCHORING OF BLOCKED SPIRAL ANCHOR LINKS IN MASONRY

. The results of experimental studies of the tensile load resistance of the anchor fastening of Sure Twist stainless steel spiral anchors, established by driving into the body of masonry products made of aerated concrete, expanded clay concrete, dense silicate concrete, porous ceramic, are presented. Repair spiral-shaped bonds are used to connect the cladding with the inner layer when reinforcing and repairing multilayer external walls, when repairing brickwork in the crack formation zone, restoring metal bonds lost due to corrosion, and also arranging vertical expansion joints in the building cladding. The method of installing spiral ties by driving masonry products into the body significantly simplifies and cheapens repair work. As a result of the studies, the dependences “load-displacement of the anchor connection” were established, on the basis of which the characteristic and calculated values ​​of the pulling load and the adhesion strength of the bonds with masonry products manufactured in the Republic of Belarus were obtained. The characteristic values ​​of the pulling load and the adhesion strength of bonds with masonry products were determined in accordance with the criteria established in the standard EN 846-6 and FCS – 44416204-09. When determining the calculated values ​​of the tensile load and the adhesion strength of the bonds, the values ​​of the characteristics of the characteristics of the material properties gM, according to TKP 45-5.03-308, depending on the class of work performance control, were assumed to be 2.0-2.5, and the value of the reliability coefficient for the material according to the breaking load m, according to the FCS – 44416204-09 equal to 3,0.      

Post Fire Residual Strength of the Wall-Slab Using Siliceous Concrete.

It is very important to understand the residual performance of a structure for repair, retrofit, and reuse of a building after a fire. In this study, an experiment is conducted on the residual performance of real-scale siliceous aggregates-based reinforced concrete (RC) wall-slab connection (WSC) after the fire, using the simple calculation method (SCM) of standards (Eurocode, ACI, and NIST) for comparison and analysis. A description of the WSC specimen and detailed methods for the experiment are introduced. The fire test is conducted according to the fire scenario by dividing it into one-sided and two-sided heating based on the wall. In the post-fire residual performance test, the load–displacement and moment-deflection angle relationship according to the fire time are derived and discussed. In addition, the residual mechanical properties after the fire are derived for the 35 MPa siliceous concrete used in the wall-slab specimen. The load and moment, derived using SCM, are compared with the experimental results. Our results show that the one-sided heating test result is close to that of Eurocode’s SCM, and the two-sided heating test result is close to that of ACI (NIST)’s SCM. This study provides a database on the residual strength through a real-scale fire test and standard comparison.