Improved Strength Properties Research Articles

A Comparison of the Geometrical Accuracy of Thin-Walled Elements Made of Different Aluminum Alloys

In modern constructions, especially aircraft, the aim is to minimize the weight of the components used. This necessitates the use of innovative construction materials, or the production of these parts with ever-decreasing wall thicknesses. To simplify assembly and improve strength properties, so-called structural elements are being used in the form of monolithic elements, which are replacing the assemblies of parts joined by, for example, riveting. These structures often have a complex, thin-walled geometry with deep pockets. This paper attempts to assess the accuracy of manufacturing thin-walled elements, in the shape of walls with different geometries, made of various aluminum alloys. Machining tests were conducted at different cutting speeds, which allowed comparisons of the geometric accuracy of parts manufactured under conventional and high-speed cutting conditions. Based on the result obtained, it was found that the elements made of EN AW-7075 T651 alloy underwent the greatest deformations during machining in comparison to other two materials (EN AW-6082 T651 and EN AC-43000). An increase in the geometrical accuracy of the manufactured elements was also observed with the increase in the cutting speed for the HSC range. Hence, to minimize the postmachining deformation of thin-walled elements, the use of high-speed cutting is justified.

Finger-jointing of green Eucalyptus globulus L. wood with one-component polyurethane adhesives

The use of glued finger joint in green wood, directly from the sawing process, would open the possibility to obtain glued timber from small-sized wood, achieving an efficient use of the original raw material. The gluing of finger-jointed green wood, with moisture content above the fibre saturation point, may improve the efficiency and the manufacturing process of glulam or joinery. This may be especially beneficial for a hardwood such as Eucalyptus globulus L., which is a globally important forest resource, but is a challenging wood to dry. This article presents a study on the possibility to develop finger joints with wood in green state. To compare them, conventional finger joints on dry wood and solid boards without end joints were also manufactured. Cold-setting and fast-curing commercial one-component polyurethane adhesive systems were used. Finger-jointed samples were tested to determine mean and characteristic values (5th percentile) of density, bending strength and modulus of elasticity, and the results were analysed and discussed. Green-glued joints showed no statistically significant differences compared to the solid boards and improved strength properties with respect to dry-glued joints.

Role of cellulose nanofibrils in improving the strength properties of paper: a review

The pursuit for sustainability in the papermaking industry calls for the elimination or reduction of synthetic additives and the exploration of renewable and biodegradable alternatives. Cellulose nanofibrils (CNFs), due to their inherent morphological and biochemical properties, are an excellent alternative to synthetic additives. These properties enable CNFs to improve the mechanical, functional, and barrier properties of different types of paper. The nanosize diameter, micrometre length, semicrystalline structure, high strength, and modulus of CNFs have a direct influence on the mechanical properties of paper, such as tensile index, burst index, Scott index, breaking length, tear index, Z-strength, E-modulus, strain at break, and tensile stiffness. This review details the role played by CNFs as an additive to improve strength properties of paper and the factors affecting the improvement in paper quality when CNFs are added as additives. The paper also includes techno-economic aspects of the process and identifies areas that need further research.

Influence of molybdenum and rhenium alloying additives on NiAl–Cr–Co cast alloy structure and properties

A centrifugal SHS casting technology was used to obtain NiAl–Cr–Co–(X) alloys where X = 2.5÷15.0 wt.% Mo and up to 1.5 wt% Re. The study covers the effect of modifying additives on the combustion process as well as the phase composition, structure, and properties of cast alloys. Alloying up to 15 % Mo and 1.5 % Re provided the highest improvement of properties in relation to the base alloy in terms of overall performance. Molybdenum formed a plastic matrix and improved strength properties to the following values: uniaxial compressive strength σucs = 1730±30 MPa, yield strength σys = 1560±30 MPa, plastic component of deformation εpd = 0.95 %, and annealing at t = 1250 °С improved them to: σucs = 1910±80 MPa, σys = 1650±80 MPa, εpd = 2.01 %. Rhenium modified the alloy structure and improved its properties to: σucs = 1800±30 MPa, σys = 1610±30 MPa, εpd = 1.10 %, and annealing further improved them to: σucs = 2260±30 MPa, σys = 1730±30 MPa, εpd = 6.15 %. The mechanical properties of the NiAl, (Ni,Cr,Co)3Mo3C, Ni3Al, (Cr, Mo) and MoRe2 phases, as well as the hypothetical Al(Re,Ni)3 phase, were determined by the nanoindentation method. According to the Guinier–Preston structural transformation, local softening upon annealing at t > 850 °С increases the proportion of plastic deformation during compression tests due to the lost coherence of the boundaries of nanosized plate-shaped Cr-based precipitates with a supersaturated solid solution. A hierarchical three-level structure of the NiAl–Cr– Co–15%Mo alloy was established: the first level is formed by β-NiAl dendritic grains with interlayers of molybdenum-containing phases (Ni,Co,Cr)3Mo3C and (Mo0.8Cr0.2)xBy with a cell size of up to 50 μm; the second one consists of strengthening submicron Cr(Mo) particles distributed along grain boundaries; the third one is coherent nanoprecipitates of Cr(Mo) (10–40 nm) in the body of β-NiAl dendrites. The cast alloy mechanical grinding techniques were used to obtain a precursor powder with an average particle size of Dav = 33.9 μm for subsequent spheroidization.

Improving the Hardened Properties of Nonautoclaved Silicate Materials Using Nanodispersed Mine Waste

The development trend of building materials science directs at on energy and resource conservation, as well as the creation of green composites. An important step in this direction is the disposal of waste of various origins, including mine waste. This study is aimed to improve the hardened properties of nonautoclaved silicate materials using nanodispersed mine waste for the use of the structural formation of wall silicate products. Binder composites obtained from sand-clay rocks of an incomplete stage of clay formation were prepared in the form of new compositions, using a modified calcareous-sandy-clay binder, based on which silicate products with improved strength properties and durability characteristics were developed. Using differential thermal analysis (DTA) and X-ray diffraction patterns, as well as scanning electron microscopy images, the synthesis of hydration products in the system sandy clay rocks–calcium hydroxide–water without a traditional autoclave treatment was also studied. The features of hydration phase formation and hardening of modified binders were investigated taking into account the chemical, structural, and morphological features of sandy-clay rocks. Meanwhile, the microstructural, morphological, and thermal properties of the silicate materials at 2-day were also determined, and their work investigated their compressive strength and water absorption. The results show that the polymineral composition of the studied sandy-argillaceous rocks, which are nanodispersed mine waste, determines the possibility of interaction with quicklime with the formation of binders during hydrothermal treatment without pressure. Accordingly, it contributes to the production of low energy consumption silicate wall materials. Cementitious composites of unautoclaved silicate materials based on sandy clay rocks have hydraulic properties that are caused by the process of further formation and recrystallization of calcium hydrosilicates, which optimizes the ratio between gel and crystalline components and compacts the structure of the cementitious composites, which leads to an increase in performance. The use of sand-clay rocks instead of traditional quartz sand in the production of silicate materials improves the process of forming the raw mix, increases the strength of silicate products by 4–11 times, and optimizes the weather resistance of wall materials.

New Eco-Friendly Coating Formulations to Improve Strength and Physical Properties of Recycled Paper Boards for Sustainable Packaging Applications

This research work emphasizes the applicability of eco-friendly clay-based coating formulation on recycled paperboards to improve strength properties. Two new clay-based coating formulations were prepared using china clay (F1) and montmorillonite clay (F2) as the main constituents and acronal, sorbitol, and ammonia as other additives. The coating was performed using K bar coater at three different thicknesses (4, 10, and 15 μm). The strength and physical properties of recycled paperboard coated with formulations F1 and F2 were compared. It was found that the strength properties of recycled paperboards coated with formulation F1 were higher, and the physical properties (porosity and cobb) were lower than formulation F2. Scanning electron microscopy (SEM) analysis indicated reducing pores and unevenness on the surface of recycled paperboards when coated with formulation F1. The atomic force microscopy (AFM) images of the recycled paperboards coated with formulation F1 revealed improved surface smoothness for a coating thickness of 4 μm.

Influence of Silicon and Magnesium on the Mechanical Properties of Additive Manufactured Cu-Al Alloy.

By using cold metal transfer technique, Cu-Al alloy with addition of silicon (Si) and magnesium (Mg), viz (1) Cu-6.5% Al and (2) Cu-6.5% Al-1.2% Si-0.5% Mg were manufactured additively. Four samples were deposited: Cu-6.5% Al alloy as samples 1 and 2, and Cu-6.5% Al-1.2% Si-0.5% Mg alloy as samples 3 and 4. The alloys were homogenized by heat treatments: (1) 800°C (2 h) for sample 2 and (2) sample 4, to improve their mechanical properties. Detailed microstructural investigation conducted using scanning and transmission electron microscopies showed formation of various intermetallic phases. Results revealed that (1) the addition of Si and Mg increases the strength properties and ductility and (2) heat treatments improved strength properties but reduce the ductility of the alloys. The article discusses the correlation of the identified microstructure and the evaluated mechanical properties of the additively manufactured alloys.

The Mechanism of Getting New Composite Polymer Materials with Improved Hardness Properties

The main aims and the objectives of the study focused on solving current problems of nanomaterial science of new materials – creating the scientific basis for competitive methods of obtaining and controlling new composite materials having improved strength properties based on carbon-containing polymer matrices with nanotubes stabilized in them. A technology for obtaining experimental samples of nanocompositional polymer material based on polymethylmethacrylate, polybutylmethacrylate, and methacrylic acid doped with carbon nanotubes has been developed, using ultrasonic action and mechanical mixing of the composite mixture to achieve the most uniform distribution of nanotubes in the matrix. To determine the possibility of implementing the mechanism of adsorption interaction of the studied polymer material with the surface of carbon nanotubes, DFT calculations of the interaction of the polymer material component and single-layer carbon nanotubes of various types have been done.

Effect of maleic anhydride grafted polylactic acid concentration on mechanical and thermal properties of thermoplasticized starch filled polylactic acid blends

Polylactic acid (PLA) is blended with native starch or thermo plasticized starch (TPS) for preparing biodegradable composites. However, poor compatibility of PLA with starch results in the composites with inferior mechanical properties. This study examines the effect of Maleic Anhydride-Grafted-PLA (GMAPLA) coupling agent and its concentration on the extent of improvements in mechanical and thermal properties of PLA –TPS blends. Maleic anhydride was grafted on PLA in Haake torque rheometer, characterized and used as the coupling agent. PLA/TPS (wt/wt) blends (70/30 and 50/50) were prepared by twin screw extrusion. GMAPLA at three different levels 5%, 10% and 15% (wt%) with respect to PLA content was taken to study its effect on mechanical properties of blends. Presence of GMAPLA significantly improved the mechanical properties (tensile, flexural and impact strength) of TPS/PLA blends. Among the three concentrations, 10% GMAPLA in the blend was found to give the maximum improvement in strength properties. Dynamic mechanical analysis and thermo-gravimetric analysis indicated no significant effect of GMAPLA content on transition temperatures and thermal degradation behavior of the blends.

Novel approach in experimental and statistical investigations on titanium matrix composite

Titanium matrix composite (TMC) is comprehensively used in aerospace, turbo-machinery, automobiles and bio-medical industries for its improved strength properties and wear, corrosion and fatigue resistance. The major aim of this paper is to focus on the development of the current state-of-art of improving the tribo-mechanical properties by developing the TMC through laser engineering net shaping (LENS) process. A novel approach has been proposed in the multi-objective optimization (MOO) technique by combining grey relational analysis with desirability, named as desirable grey relational analysis (DGRA). The main advantage of incorporating such, is to include the predicted responses obtained by response surface methodology (RSM) with the actual experimental performances. Advanced non-traditional machining like wire electro-discharge machining (WEDM) has been used for the experimental runs on the developed TMC by varying power (P), time off (Toff) and peak current (IP) as chief input process parameters. Box–Behnken design (BBD) model has been projected to obtain MOO on key performance measures, like material removal rate (MRR), surface roughness (SR), kerf width (KW) and over cut (OC). The optimized solution is improved by 1.022% when compared with desirability approach to novel DGRA technique. MRR is enhanced by 1.463%, SR by 13.221%, KW by 1.594% and OC by 6.025% when compared with DGRA method.

Pervious concrete: the art of improving strength properties

Urban cities in Malaysia are highly vulnerable to flash floods due to improper drainage system and the impermeable road surface. The Pervious Concrete (PC) Pavement for urban water management indicates the implementation of this system shows promising results to reduce flash flood volume and among the mitigation that can be applied is by adopting the permeable pavement systems. This was based on a case study of Sponge City in China. Since the properties normally consist of coarse aggregate only / or less fine aggregate to fill in the void structure. Regardless of the high advantage of these systems to reduce the flooding impact, this permeable pavement is known for its lower strength. Due to this fact, it is rare and impossible for this permeable pavement to be utilized at the main road and highway. Whereas, currently in Malaysia, the permeable concrete is only accustomed to light traffic loadings such as walkways and car park. This paper was discussing the way to improve the strength properties of PC pavements with a focus on sustainable development.

Propolis and Organosilanes as Innovative Hybrid Modifiers in Wood-Based Polymer Composites.

The article presents characteristics of wood/polypropylene composites, where the wood was treated with propolis extract (EEP) and innovative propolis-silane formulations. Special interest in propolis for wood impregnation is due to its antimicrobial properties. One propolis-silane formulation (EEP-TEOS/VTMOS) consisted of EEP, tetraethyl orthosilicate (TEOS), and vinyltrimethoxysilane (VTMOS), while the other (EEP-TEOS/OTEOS) contained EEP, tetraethyl orthosilicate (TEOS), and octyltriethoxysilane (OTEOS). The treated wood fillers were characterized by Fourier transform infrared spectroscopy (FTIR), atomic absorption spectrometry (AAS), and X-ray diffraction (XRD), while the composites were investigated using differential scanning calorimetry (DSC), X-ray diffraction (XRD), and optical microscopy. The wood treated with EEP and propolis-silane formulations showed resistance against moulds, including Aspergillus niger, Chaetomium globosum, and Trichoderma viride. The chemical analyses confirmed presence of silanes and constituents of propolis in wood structure. In addition, treatment of wood with the propolis-silane formulations produced significant changes in nucleating abilities of wood in the polypropylene matrix, which was confirmed by an increase in crystallization temperature and crystal conversion, as well as a decrease in half-time of crystallization parameters compared to the untreated polymer matrix. In all the composites, the formation of a transcrystalline layer was observed, with the greatest rate recorded for the composite with the filler treated with EEP-TEOS/OTEOS. Moreover, impregnation of wood with propolis-silane formulations resulted in a considerable improvement of strength properties in the produced composites. A dependence was found between changes in the polymorphic structures of the polypropylene matrix and strength properties of composite materials. It needs to be stressed that to date literature sources have not reported on treatment of wood fillers using bifunctional modifiers providing a simultaneous effect of compatibility in the polymer-filler system or any protective effect against fungi.

The effectiveness of waste oyster shells (WOS) as major fine aggregate replacement in concrete

Over-exploitation of natural river sand and waste oyster shells (WOS) dumped randomly will cause serious environmental issues. Thus, a drive to using crushed WOS as fine aggregates to substitute river sand in concrete production has been initiated. This paper conducted experimental research to study the possibility of employing the crushed WOS as 100% fine aggregates in concrete. The workability, compressive strength and its size-effect, and sustainability performance of the concrete mixtures were investigated. The results indicated that, under the same water-cement ratio, the WOS concrete showed a great improvement in strength properties while a decline was found in slump tests, compared to the control concrete. Besides, the use of the crushed WOS in concrete production resulted in a modification in both eco-efficiency and cost-efficiency.

Role of engineered fibers on fresh and mechanical properties of concrete prepared with GGBS and PVC waste powder – An experimental study

This research reports the experimental investigation, capturing the effect of engineered fibers on fresh and mechanical properties of M50 grade concrete blended with poly-vinyl chloride (PVC) waste powder with one mineral admixture and one chemical admixture as superplasticizer. In this experimental investigation fourteen mixes (seven mixes with fibers and seven mixes without fibers) are prepared using ground granulated blast furnace slag (GGBS) as mineral admixture and PVC waste powder. In these mixes PVC waste powder content is varied in 0% (treated as reference mix), 5%, 10%, 15%, 20%, 25% and 30% by weight of cement whereas, 30% of GGBS is kept constant except reference mix. 0.6% of sulpho-naphthalene formaldehyde (SNF) as superplasticizer, by weight of cement are kept constant in all the mixes. Similarly, to study the effect of fibers on fresh and mechanical properties of concrete, 0.5% of engineered fibers are used along with 0.6% of superplasticizer. So that a comparison between with and without fibers could be prepared. Fresh properties of concrete are studied by using slump and compaction factor test for all the mixes. Similarly, the prepared test specimens are tested for the mechanical properties like compressive, flexural and split tensile strength as per Indian standard IS:516-1959 at 7, 14, 28and 90-days curing period. Test results indicates that up to 20% PVC waste powder can be used as a partial replacement of cement along with 30% GGBS, 0.6% of SNF superplasticizer, and 0.5% fibers in M50 grade concrete without compromising strength properties. Use of engineered fibers along with GGBS and PVC waste powder not only helps in reducing the cement consumption, but also improves strength properties and facilitates in lowering the cost of construction.

Reinforcement potential of modified nanofibrillated cellulose in recycled paper production

The influence of nanofibrillated cellulose (NFC) was investigated as a reinforcing agent to improve strength properties of papersheets fabricated from recycled pulp fibers of mixtures of old newspapers, old magazines, and old corrugated cardboards. To determine the effects of the NFC on the mechanical and physical properties of the recycled pulp papers, cellulose nanofibrils (NFC) were isolated from wheat straw, pretreated chemically and enzymatically (NFC-OX), and then added to the bulk suspensions of papermaking pulp slurries at various percentages. The electrokinetic and drainage properties of the pulps and the mechanical and physical properties of the papersheets were analyzed and compared. As expected, the addition of NFC/NFC-OX significantly increased the strength properties of papers. Papers containing 4% of NFC-OX (periodate pretreated) presented higher increases in tensile index (43%) and burst index (59.3%) than other papers. However, a high addition of NFC/NFC-OX increased the water retention, which is undesirable for papermaking. Hence, with optimum selection of NFC/NFC-OX and process conditions, higher mechanical properties could be acquired without increasing drainage rate. Compared to the other pretreated NFC/NFC-OX types, sodium-periodate-oxidized NFC-OX samples significantly increased the mechanical properties of the papers fabricated from the recycled pulps.

Effect of direct microalloying of boron-containing structural steels on their structure and mechanical properties

In conditions of converter shop of JSC “ArcelorMittal T tau” the authors have developed and implemented the technology of direct microalloying of structural steels with boron. Microalloying was carried out due to 2 boron recovery from the slags of the CaO – SiO 2 – B 2 O 3 – MgO – Al 2 O 3 system formed in ladle furnaces. The use of the developed technology provided in steels 08KP, 3SP, 3PS and 09G2S boron content of 0.0016 – 0.0050 %, a sufficiently high degree of metal desulfurization 36.8 – 51.7 %, reduction in manganese ferroalloys consumption by 0.3 – 0.6 kg/t of steel, improving the environmental situation by eliminating the use of fluorspar. For 09G2S steel the yield σ y and tensile σ t strengths are higher for the experimental metal then for the steel without boron by an average 27 and 24 MPa, respectively. Percentage of elongation of the metal with boron increased by an average 0.2 %. Grain-size index of rolled metal of 08KP steel with a thickness of 2.0 – 2.5 mm, containing 0.001 % of boron and a manganese concentration lowered to 0.18 %, reaches 10.0 in contrast to 9.0 for the heats of the current production. The yield σ y and tensile σt strengths are on average by 6.0 and 5.0 MPa higher for an experimental metal than for a comparative one. Percentage of elongation δ reaches 36.3 % for the experimental metal unlike 33.3 % for the heats of the current production. Experimental rolled metal of 3PС steel with lower concentration of manganese lowered by 0.02 % and with an average boron content of 0.001 % is characterized by an increased yield strength σ y , tensile strength σ t (on average by 2.0 and 9.0 MPa) and percentage of elongation δ reaching in average 21.0 %, and fine-grained structure. Rolled metal of 3SP steel, microalloyed with boron, with a thickness of 4 mm that contains manganese content reduced to 0.43 % is characterized by improved strength properties with preservation of plastic characteristics. The absolute value of the yield σ y and tensile σ t strengths of steel are by 4.0 and 2.0 MPa higher than the strength characteristics of steel without boron.

Recent Progress in Hybrid Biocomposites: Mechanical Properties, Water Absorption, and Flame Retardancy.

Bio-based composites are reinforced polymeric materials in which one of the matrix and reinforcement components or both are from bio-based origins. The biocomposite industry has recently drawn great attention for diverse applications, from household articles to automobiles. This is owing to their low cost, biodegradability, being lightweight, availability, and environmental concerns over synthetic and nonrenewable materials derived from limited resources like fossil fuel. The focus has slowly shifted from traditional biocomposite systems, including thermoplastic polymers reinforced with natural fibers, to more advanced systems called hybrid biocomposites. Hybridization of bio-based fibers/matrices and synthetic ones offers a new strategy to overcome the shortcomings of purely natural fibers or matrices. By incorporating two or more reinforcement types into a single composite, it is possible to not only maintain the advantages of both types but also alleviate some disadvantages of one type of reinforcement by another one. This approach leads to improvement of the mechanical and physical properties of biocomposites for extensive applications. The present review article intends to provide a general overview of selecting the materials to manufacture hybrid biocomposite systems with improved strength properties, water, and burning resistance in recent years.

Effect of bacteria subtilis on e-waste concrete

Abstract Concrete is considered to be the greatest consumers of natural resources, which forms dominant material in the construction Industry. Concrete possess very low tensile strength and it cracks under uninterrupted loading. Due to destructive environmental agents, life of the structure is conclusively reduced which were constructed using concrete materials. This type of damage is caused beforehand of the building structures life and also in due course of time. Epoxy injection methods are used to countermeasure this problem of formation of cracks. But they are not agreeable. Therefore, a different and eco-friendly method of crack arresting called Microbiologically Induced Calcium Carbonate (calcite) Precipitation has been proposed to improve the strength of construction materials. In this paper the issues of environmental concern were addressed and the use of E-waste as a substitution for coarse aggregate was planned to attempt. M30 grade of concrete mix design was adopted. E-waste in the range of 0%, 5%, 10%, 15% and 20% to that of coarse aggregate has been substituted. Percentage of microorganism varies as 1% & 2% of the cement content. Finally, the mechanical properties of concrete mix are obtained and compared with control concrete mix. Remarkable improvements in strength properties were reported.

Improved strength properties of LVL glued using PVAc adhesives with physical treatment-based Rubberwood (Hevea brasiliensis)

Abstract The properties of the laminated veneer lumber (LVL) composed of the boiled veneer of Rubberwood (Hevea brasiliensis) using polyvinyl acetate (PVAc) adhesives in various cold-pressing time and various conditioned time with loaded and unloaded were studied. Five-ply LVL was produced by boiling veneer at 100°C for 90 min as pretreatment and cold-pressing time at 12 kgf cm−2 for 1.5, 6, 18, and 24 h then conditioned at 20°C and 65% relative humidity (RH) with loaded (12 kgf cm−2) and unloaded for 7 days as physical treatment. Especially for the delamination test, the specimens were immersed at 70 ± 3°C for 2 h and dried in the oven at 60 ± 3°C for 24 h; then, the specimens were solidified at room temperature (20°C and 65% RH) with loaded (12 kgf cm−2) and unloaded for 7, 10, 12, and 14 days. To determine the performance of LVL, the density, moisture content (MC), delamination, modulus of elasticity (MOE), modulus of rupture (MOR), horizontal shear strength, and formaldehyde emission tests were conducted according to the Japanese Agricultural Standard (JAS 2008) for structural LVL. The MOE and MOR values were significantly influenced by the physical treatment, however, neither to horizontal shear strength nor to formaldehyde emission. The best performance of LVL has resulted from unloaded LVL with cold-pressed time for 18 h; the MOE and MOR values were 9,345.05 ± 141.61 N mm−2 and 80.67 ± 1.77 N mm−2, respectively. The best value of the horizontal shear strength was obtained from the LVL with 18 h cold-pressing time and conditioned with loaded (13.10 ± 1.47 N mm−2) and unloaded (12.23 ± 1.36 N mm−2). The percentage of delamination values decreased with an increase in the cold-pressing time and conditioning time. The lowest value of delamination (19.06%) was obtained from the LVL with 24 h cold-pressing time and conditioned with loaded for 14 days. Except the delamination test, all other properties fulfilled the JAS.

Thermal Conductivity and Strength Properties of Nanosilica and GGBS Incorporated Concrete Specimens

An important property which affects the heat transfer process in buildings and to minimize the usage of artificial energy in buildings is thermal conductivity. The transfer of heat through walls and roofs determines the amount of artificial energy required in the buildings. The conventional methods used to determine the thermal conductivity of buildings are transient and steady state methods. The objective of this paper is to measure the thermal conductivity of concrete specimens replacing nanosilica and GGBS by weight of ordinary Portland cement. Nanosilica was replaced by weight of cement in different proportions ranging from 1% to 5%. Addition of nanosilica and GGBS in concrete improves the compressive strength and split tensile strength of concrete by around 10%. Improvement in strength properties is mainly due to densification of concrete microstructure by filling pores in concrete specimens. In addition to the strength characteristics, nanosilica incorporated concrete specimens showed better thermal resistance as compared with conventional concrete mix. Lower heat transfer rate is due to the better particle packing nature of nanoparticles in concrete. Nanosilica acts as better heat retarding agent in concrete and thus it minimizes the use of artificial energy in the buildings. It is concluded that utilization of nanosilica reduces the heat transfer rate in to the buildings and the optimum amount of nanosilica was found to be 3% by weight of cement.