Abstract:Biological building materials are new green building materials made from agricultural and forestry waste through physical,chemical or biological processing methods.Their core advantages lie in the renewability of resources,low carbon emissions,environmental friendliness,economic efficiency,and excellent design performance,such as light weight and high strength,heat insula-tion,sound absorption and fire protection,health and comfort.The main classifications include inorganic cement-based,organic poly-mer-based and composite-based biological building materials.They are applied in areas such as wall structures,insulation and heat preservation,and decorative sound absorption.The current production process covers raw material pretreatment,composite molding and post-processing technology.However,challenges remain in performance stability,interface compatibility,high costs,and incom-plete policy standards.Future development should focus on high-performance integration and multifunctional integration.This re-quires improving the standard system,increasing policy support,and building a circular economy industrial chain to promote large-scale applications in green buildings,low-carbon building materials,and rural revitalization.

Abstract:This paper analyzes the accuracy of testing the thermal conductivity of plates using the steady-state guarded hot plate method from four aspects:equipment stability,human factors,laboratory environmental conditions,and the quality of the plates themselves.The results show that thermal conductivity instruments should be calibrated regularly to maintain test stability and im-prove the accuracy of test results;the thickness of the sample is directly proportional to the thermal conductivity—when the thick-ness increases or decreases by 1mm,the thermal conductivity change rate ranges from 2.86%to 5.31%,so the thickness should be measured multiple times to reduce measurement errors;changes in the temperature and humidity environment of the laboratory will affect the accuracy of thermal conductivity measurement of graphite extruded boards—for every 10℃increase in the laboratory temperature,the measured thermal conductivity value increases by 5.6%,and for every 10%increase in humidity,the measured thermal conductivity value increases by 3.1%;the thermal conductivity of graphite extruded boards is affected by aging time,and it changes with aging time,first increasing and then tending to be stable.

Abstract:The effect of high-volume use of low-grade limestone powder on the performance of cement mortar was systematically studied.A composite method for multi-component cementitious system based on viscosity-reducing and strength-enhancing agents(VRSEA)and low-grade limestone powder(LGLP)was established.The influence mechanism on hydration products and pore structure was investigated by means of X-ray diffraction(XRD),scanning electron microscopy(SEM)and mercury intrusion porosimetry(MIP).The results showed that the high-volume addition of LGLP exerted an adverse effect on the mechanical properties of cement mortar,while the multi-component cementitious system based on VRSEA could mitigate such negative impact effectively.When the dosage of VRSEA is 10%of the system,the 28-day compressive strength of cement mortar increased by 16.1%,and the influence coefficient of compressive strength was improved by 0.09.The feasibility of this technical approach was verified by C10 concrete tests.Microscopic analysis indicated that the multi-component cementitious system reduced the content of calcium hydroxide,modified the morphology of hydration products,and decreased the volume of harmful and extremely harmful pores.

Abstract:In order to enhance the bonding strength of inorganic waterproof and plugging materials on special substrates,this study investigated the efficacy of interfacial agents applied to four distinct surfaces:acrylic,porcelain tile,stainless steel,and glass.Interfacial agents,formulated with varying ratios of three different emulsions-waterborne epoxy,chloroprene rubber,and a hybrid emulsion-were applied to each substrate.Subsequent bond strength tests were conducted to assess the substrate adaptability of each interfacial agent and to analyze the factors influencing the resultant bond strength.The findings demonstrate that the interface agent employing the chloroprene rubber configuration exhibits multi-substrate adaptability,resulting in a significant enhancement of bond-ing strength across acrylic,stainless steel,and glass substrates.There is no significant difference in the bonding strength of three kinds of pure emulsion interfacial agents due to the mechanical locking effect of porous rough structure of porcelain brick substrate.The impact of liquid-to-powder and ash-to-sand ratios on the bonding performance of the paste is contingent upon the substrate type.Consequently,the proportion of interface agent should be calibrated with respect to the specific substrate to optimize interfacial adhesion.

Abstract:In this study,the enhancement effect and mechanism of basalt fiber dosage on the low temperature cracking resistance of 90#road asphalt mixture,SBS modified asphalt mixture and rubber powder modified asphalt mixture under the condition of 0,-10 and-20℃using the semi-circular bending test method.The results indicate that the optimal content of basalt fiber is 0.30%.At this content,compared to those without basalt fiber,the ultimate tensile stress of 90#asphalt mixture,SBS modified asphalt mixture,and rubber powder modified asphalt mixture under-20℃low temperature conditions increased by 11.45%,9.17%,and 12.92%respectively,the fracture toughness increased by 17.85%,10.75%,and 19.23%respectively,the fracture energy increased by 33.28%,57.53%,and 55.97%respectively.When the temperature decreases from 0 to-20℃,the fracture energy attenuation rate of the crumb rubber-modified asphalt mixture is reduced by 21.61%relative to the control mixture without fiber reinforcement.

Abstract:This study investigates the effects of rice-straw fiber diameter,sand-to-binder ratio(S/B)and superplasticizer dosage on the flowability,extrudability,buildability and mechanical performance of 3D printing rice straw fiber reinforced cement-based composites(3DPRSFCC).Results show that flowability decreases markedly with increasing fiber diameter,whereas it improves with higher S/B and superplasticizer content.An optimal balance is achieved with 0.6 mm-diameter fibers(3～5 mm long),S/B=1∶1 and 0.10%superplasticizer:under this mix the composite exhibits the best extrudability,buildability and mechanical properties,a low co-efficient of variation in printed filament width,and enables stable construction of a 10-layer hollow cylinder with a cumulative de-formation of only 31.5%.The corresponding 28-day flexural and compressive strengths reach 3.21 MPa and 5.20 MPa,respectively.The work provides reference for valorizing rice straw and for deploying rice straw fibers in 3D concrete printing.

Abstract:Taking a large public building project in Shijiazhuang,Hebei Province as an example,relevant materials and equip-ment were prepared according to construction requirements.By calculating key parameters such as the number of prestressed steel bars,cutting length,and concrete beam deflection,the construction sequence and process of the prestressed frame beam concrete structure with slow bonding were optimized.The quality of the construction results was further verified through compressive and tensile strength tests.The research results show that the optimized concrete structure can withstand a maximum pressure of 1000 N,with a tensile strength significantly lower than 5 MPa and a prestress loss of only 0.19 N,all of which meet the preset requirements.This indicates that the delayed bonding prestress technology can effectively improve the construction quality and performance of the prestressed frame beam concrete structure with slow bonding.

Abstract:A polycarboxylic acid water-reducing mother liquor and a slump-retaining mother liquor were synthesized in this paper.The main synthetic factors were optimized through single factor test method,and it is compounded with defoaming agents,air entraining agents and retarders to investigate its performance in concrete.Experiments show that the optimal synthesis formula of polycarboxylic acid water-reducing mother liquor is:[n(AA)∶n(TPEG)]4.0,dosage of both AMPS and SMAS is 2%of the mass of the macromonomer,the initiation system is H2O2/Vc,dosage of H2O2 initiator is 1%of the mass of the macromonomer.The mini-mum saturated dosage of the polycarboxylic acid water-reducing mother liquor synthesized with the optimal formula is 0.3%,and at this dosage,its water reduction rate is as high as 25.33%.The optimal synthesis formula of polycarboxylic acid slump-retaining mother liquor is as follows:dosage of H2O2 initiator is 0.9%of the mass of the macromonomer;the molar ratio of HEA,HPA,dimethyl itaconate and dimethyl fumarate is 9∶3∶2∶2;and the dosage of compounding agent is 4%of the mass of the macromonomer.The fluidity of cement paste with 0.2%slump-retaining mother liquor prepared with the optimal ratio was still able to reach 275 mm at the 4th hour,indicating that it has good slump-retaining performance.The compounding test shows that the two mother liquors can meet the actual engineering needs.

Abstract:By incorporating lithium slag and polypropylene fibers into concrete,three different types of concrete were designed:plain concrete(PC),lithium slag concrete(PLiC),and polypropylene fiber lithium slag concrete(PFLiC).The effects of simulated salt-affected environments with different immersion ages on the compressive strength,splitting tensile strength,flexural strength,and dy-namic elastic modulus of different concretes were studied.The results show that the mechanical properties and performance degrada-tion rate of PFLiC are superior to those of PC in a salt-affected environment.The dual addition of lithium slag and polypropylene fibers in concrete can improve the mechanical properties of concrete in a salt-affected environment.A compressive strength damage model under salt-affected environments was proposed,and the fitting effect of PFLiC was better,with R2 being 0.99859,which can better simulate the evolution law of compressive strength deterioration of PFLiC in simulated salt-affected soil solution.Based on the obtained strength damage model,the predicted compressive strength lifetimes of PC,PLiC,and PFLiC in a simulated salt-affected en-vironment were 135,148,and 177 d,respectively.

Abstract:Gypsum blocks are construction products primarily made from building gypsum and water,produced through process-es such as casting,semi-dry pressing,or extrusion.Over the past decade,changes have occurred in their raw materials and manufac-turing techniques.This article introduces the key revisions in the JC/T 698-2025 standard"Gypsum Blocks",detailing over ten ma-jor technical differences between the new and old standards to facilitate better understanding and application by users.The imple-mentation of this standard will further promote the large-scale and industrialized application of gypsum block products,enhance ar-chitectural decoration,reduce energy consumption and emissions,and improve the quality of construction projects.

Abstract:To tackle the high energy consumption and pollution associated with conventional artificial aggregate production,this study employs industrial solid wastes including sludge,carbide slag,and desulfurization gypsum to fabricate high-strength artificial aggregates via hydrothermal curing.By varying the calcium-to-silicon ratio(Ca/Si=0.4～1.0),the resistance to water,acid,dry-wet cycles and freeze-thaw cycles was studied and compared with that of natural aggregates in practical applications.Results demon-strate that at Ca/Si=0.9,the aggregate achieves a peak unconfined compressive strength of 39.1 MPa and a softening coefficient of 0.85.Moreover,it exhibits superior resistance to acid,freeze-thaw cycles,and dry-wet cycles compared to other ratios.When crushed and applied in a water-stabilized macadam base course,the aggregate shows performance close to that of natural aggre-gates.The 7-day unconfined compressive strength,flexural tensile strength and elastic modulus of artificial aggregates are close to that of natural aggregates,and the water absorption and crushing value meet the requirements of standard JTG/T F20-2015"Tech-nical Guidelines for Construction of Highway Roadbases".

Abstract:In the middle and upper sections of geothermal boreholes,a portion of geothermal energy is transferred through the casing wall to lower-temperature strata,the acidic conditions in the formation can diminish the durability of the cement.In this study,diatomite was incorporated to prepare cement specimens,and the performance changes of diatomite cement test blocks before and after corrosion in different acidic environment were analyzed using scanning electron microscopy,mercury intrusion porosimetry,and thermal conductivity measurement.The results indicate that when the diatomite content is 16%,the compressive strength of cement test blocks at various ages is higher,significantly higher than that without diatomite;the corrosion resistance of cement test blocks is improved by adding diatomite;as the diatomite content increases,the thermal conductivity of cement test blocks decreases significantly,with a maximum reduction of up to 26%.This is because the addition of diatomite can refine pores,making the pore distribution more uniform,and the hydrated calcium silicate and calcium hydroxide generated by the pozzolanic reaction between SiO2 and cement have low thermal conductivity.

Abstract:Slag was used as the main aggregate,fly ash and desulfurization gypsum were used as cementitious materials to re-place part of the cement to study the effects of single addition of fly ash and combined addition of fly ash and gypsum on the me-chanical properties and microstructure of lightweight concrete,and investigate its reaction mechanism through microscopic analysis such as scanning electron microscopy(SEM)and X-ray energy spectroscopy(EDS).The results show that when the slag content in the con-crete is 70%and the single fly ash content is 10%,the 28 d compressive strength reaches 27.12 MPa,and the dry apparent density is 1758.31 kg/m3.When double doped fly ash of 10%and desulfurization gypsum of 30%,the 28 d compressive strength of lightweight concrete reaches 20.81 MPa,and the dry apparent density reaches 1703.51 kg/m3.The incorporation of fly ash and desulfurization gyp-sum with appropriate ratio changed the growth orientation of Ca(OH)2,which make the hydration products more uniform and dense.

Abstract:Based on modified starch,a composite starch based hydration heat inhibitor was prepared using various functional components such as chitosan-polyacrylate coating material,disodium EDTA,sodium methylsilicate,and active siliceous reinforcement material,and the effects of the composite starch based hydration heat inhibitor on the temperature rise performance,crack resis-tance,and waterproof performance of cement-based materials were studied.The results showed that compared with inhibitors without any admixture,composite starch based hydration heat inhibitors exhibit better temperature suppression,crack resistance,and water-proofing effects on cement-based materials.Mixed with 1%composite starch based hydration heat inhibitor FY-3 which prepared with 20%modified starch,15%chitosan-polyacrylate coating material,25%EDTA disodium,20%sodium methylsilicate,and 20%active siliceous reinforcement materials,the temperature suppression rate of cement paste reached 42.0%,the compressive strength ratio of 28 day concrete reached 106.3%,the concrete penetration height was 1.9～3.3 cm,and the anti cracking performance ratio of flat mortar reached 85.1%.

Abstract:Since several hundred years ago,anti-fouling coating materials(AFCMs)have been widely researched and used on the surfaces of various marine environmental facilities such as ships and pipelines,playing a role in preventing the attachment of various organisms such as microorganisms,plants,and animals in water.This article mainly reviews the development history,theoreti-cal research,performance characteristics,and application technologies of AFCMs,and thereby puts forward some suggestions on the future development of AFCMs.

Abstract:This study uses fly ash and steel slag as primary raw materials,with talc and potassium feldspar as fluxing agents,to prepare foamed ceramics via the in-situ foaming method.The study systematically investigates the influence of raw material composition on the physical properties,mineral composition,and pore structure of the foamed ceramics.The results indicate that high-temperature sintering can achieve significant spontaneous foaming effects without the addition of foaming agents.The optimal preparation process was determined to be a mass ratio of fly ash:steel slag:talc:potassium feldspar of 60:20:10:10.At this ratio,the samples exhibited the following characteristics:bulk density of 0.90 g/cm3,flexural strength of 9.74 MPa,water absorption rate of 10.05%,total porosity of 71.95%,and closed-cell porosity of 65.68%.

Abstract:Using anatase nano-TiO2 as the photocatalytic component,a photocatalytic inorganic artificial stone was prepared by embedding the catalyst into the matrix via an internal doping method.The photocatalytic performance was systematically evaluated through degradation experiments of methylene blue solution and formaldehyde gas under visible light irradiation.Results demonstrate that the degradation efficiency of methylene blue reached 85.6%at a TiO2 dosage of 7.5%,while the formaldehyde degradation ef-ficiency was 68.3%at a 5.0%dosage,retaining over 95%of its initial efficiency after six months of service.Surface glossiness analysis revealed that matte finishes significantly enhanced early-stage reaction rates due to higher light absorption.The material exhibits efficient pollutant degradation and long-term stability.

Abstract:This study employs various high-strength steel wire cloth types to conduct static loading tests on prefabricated slabs following reinforcement treatment.Finite element analysis is utilized to simulate the tested slabs.The findings indicate a close alignment between the finite element simulation and experimental results.Specifically,the reinforcement using high tensile steel wire cloth-polymer mortar effectively enhances the cracking and ultimate loads of the precast panels,resulting in a bearing capacity in-crease of over 40%.For identical specifications of high-tensile steel wire cloth,the ultimate load improvement surpasses the crack-ing load enhancement.As the number of high tensile steel wire bundles per unit width increases,the deflection at the center span bottom of the panel also rises.Notably,the prefabricated plate exhibits superior ductility,particularly when reinforced with G450 or higher-grade high-tensile steel wire cloth,which prevents immediate brittle fracture upon reaching the ultimate deflection state.Furthermore,while cracking occurs when the mid-span deflection deformation reaches the permissible deflection L0/200,it does not signify the attainment of the ultimate state.

Abstract:A two-step prepolymer method was used to chemically graft polydimethylsiloxane(PDMS)segments onto the main chain of polyurethane(PU)to prepare a structurally uniform block copolymer(PU-b-PDMS),which was applied as a primer for sili-cone sealant in ballastless track.The results demonstrate that the optimal comprehensive performance is achieved when m(PDMS)/m(PU)=0.3,MDIis selected as the hard segment,PPG-2000 serves as the soft segment,and n(—NCO):n(—OH)=1.8.Under these conditions,the copolymer exhibits a bond strength of 4.64 MPa with concrete,achieves 100%cohesive failure with silicone sealant,and possesses suitable curing speed and storage stability.FT-IR analysis confirms the successful synthesis of the target product,combining the strong adhesion of polyurethane and excellent compatibility of silicone.

Abstract:In order to investigate the high temperature resistance of the new epoxy concrete,the compressive strength test at high temperature was carried out with temperature and temperature holding time as the parameters,and the failure condition of the test block were analyzed.The research shows that as the temperature rises,the damage degree of the new epoxy concrete gradually increases,and the compressive strength of the gradually decreases.At 100℃for 2 h,the compressive strength loss exceeds 85%,and at 200℃,the compressive strength is only about 3 MPa.The new epoxy resin concrete has poor high temperature resistance and is sensitive to high temperatures.Without external insulation measures,it is not suitable for high temperature environments and is diffi-cult to be used as the main material in structures that may be exposed to high temperature environments.Based on the test results,the formula for calculating the compressive strength of new epoxy concrete at high temperature is fitted.