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Due to the growing number of biomass boiler plants there are rapid growth of biomass combustion by-products. The key point of this investigation is to utilize biomass bottom ash (BBA) and silicagel by-product (SB) in the matrices of alkali activated binders. BBA and SB are the main ingredients of aluminumsilicate precursor. This aluminosilicate precursor is a potential initial material for the preparation of alkali activated materials (AAMs). Currently, in Lithuania there are more than 160 biomass boiler plants and few more are under construction. These types of plants generate more then 25–30 thousand tons of BBA. In this paper, the compressive strength of alkali activated binders specimens was dependent on the amounts of SB and alkali activator. The hydration products of AAMs were analyzed by XRD, SEM and FT-IR. The highest compressive strength (21.6 MPa) was observed in specimens based on biomass bottom ash and 35% of SB. This blended mixture of the locally available by-product (BBA and SB) have potential to produce eco-friendly AAMs binder.

In the construction industry, the selection of sustainable materials leads to a movement towards more sustainable construction. In this study, lightweight aggregate shotcrete based on expanded glass (EG) and expanded clay (EC) is investigated. The goal of the study is to determine the influence of EG and EC inclusion on the properties of shotcrete. Ordinary Portland cement (OPC) powder with supplementary cementitious materials, such as silica fume and ground glass waste, are used as binders. The mechanical, physical and morphological properties, as well as the mineral and oxygen compositions, are obtained through compressive and flexural strength tests, thermal conductivity measurements, scanning electron microscopy with energy dispersive X-ray spectrometry (SEM–EDX), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analysis. In this study, the mechanical, physical and thermal properties and waste utilization as cement supplementary materials are balanced. The shotcrete samples show that a density of 790 kg/m3 had a good thermal performance (thermal conductivity coefficient of 0.174 W/(m·K)) with the sufficient compressive strength of 6.26 MPa.

In the petroleum industry during a catalytic cracking process, the used zeolitic catalyst becomes waste. This article investigated the sorption capacities of ammonium ions from aqueous solutions onto the previously mentioned zeolitic waste by batch experiments. Three types of zeolitic waste were used: unmodified zeolitic waste with two different particle size distributions and H2O2-modified zeolitic waste. Several techniques, including X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) multilayer adsorption theory measurements, and X-ray fluorescence analysis (XRF) were used to demonstrate experimentally that the zeolitic waste could be used as a sorbent for the water decontamination of NH4+ ions. The morphology of zeolitic waste investigated by scanning electron microscopy (SEM) revealed particles with a spherical shape. The nitrogen adsorption–desorption isotherms showed an isotherm mixture of types I (pure microporous) and IV (mesoporous). This suggested that the investigated zeolitic materials were mesoporous (4.84 nm) and microporous (0.852 nm), as well as containing slit/cylindric pores, according to a quench solid density functional theory (QSDFT) adsorption branch model. Zeolitic waste from the oil industry showed good NH4+ sorption properties (removal efficiency of 72%), thus becoming a potential adsorbent to be used in the treatment of contaminated aqueous effluents polluted with ammonium ions. Simultaneous waste and water decontamination can be achieved, providing a new tool and enhanced capabilities for environmental remediation.

Generally, the early strength of hardened Portland cement paste is controlled, by changing the mineral composition of clinker and grinding fineness. By using clinker (calcium silicates) and liquid glass (sodium silicate) together, these materials have high degree of coagulation and rapid hardening. For this reason, it is important to regulate the setting times. One solution of this problem is the use of chemical admixtures. In this research, the admixture made from liquid glass and AlF3 production waste was suggested (the waste from phosphates fertilizers production). The cement system “Portland cement clinker–sodium silicate hydrate–AlF3 production waste” was characterized by X-ray diffraction, differential scanning calorimetry, measurements of hydration temperature and the compressive strength of hardened cement paste specimens. The microstructure of hardened cement pastes was evaluated by scanning electron microscopy. Reference specimens were made from pure Portland cement clinker. A possibility to regulate hydration rates both at the early stage of hardening and at the later ones by addition of this admixture was demonstrated. The effect of AlF3 production waste was described. By using this admixture, the hydration temperature increased, the hydration process delayed, and compressive strength of hardened Portland cement clinker paste samples increased, especially at later ages. This gave the opportunity for composition: clinker–liquid glass–AlF3 production waste to create slowly curing cement; which is suitable for long transportation and for massive constructions.

Concrete plants accumulate large amounts of concrete wash water. This water, which pH is highly alkaline, has a negative impact on the environment. Its reuse in fresh concrete slightly reduces its mechanical properties. The combination of concrete wash water and zeolitic by-product led to an increase of 4.6% in the compressive strength at 7 days hydration and up to 30% at 28 days hydration. The same combination led to the denser microstructure compared to the samples made with concrete wash water. This could be explained by the pozzolanic reaction of the zeolitic by-product. The complex chemical reactions of cement, zeolitic by-product, and fines presented in the concrete wash water occurred. Therefore, it was suggested the reusing method of concrete wash water together with zeolitic by-product in the fresh concrete mixtures by substituting some amount of tap water with concrete wash water. In this way, the consumption of tap water is possible to reduce in cement systems.

Fluid catalytic cracking (FCC) catalysts, used in the petroleum industry, are sources of zeolitic by-products. These by-products are often used as sorbents for the removal of ammonium ions from wastewater. After a period of use, the zeolitic by-product loses its sorption properties and is no longer effective. The problem is the use of zeolitic by-product with ammonium ions. In this study, a zeolitic by-product containing ammonium ions and high contents of active SiO2 and Al2O3 was used as a supplementary cementitious material (SCM). Cement pastes containing 0.5%, 1%, 3%, 5%, and 10% of the by-product were prepared, and the compressive strength and density of the pastes were evaluated. Incorporation of the zeolitic by-product increased the cement strength by 17% and 32% after 7 and 28 days of hydration, respectively. Thus, incorporation of the zeolitic by-product with ammonium ions as an SCM has a complex effect on an ordinary Portland cement (OPC) system. Ammonium chloride accelerated cement setting after 7 days of hydration, and the pozzolanic reaction positively affected strength development after 28 days of hydration. The reaction products caused the cement to have a compact microstructure. The zeolitic by-product containing absorbed ammonium ions can be successfully reused to replace ordinary Portland cement in cement pastes.

There is a growing interest in the development of new cementitious binders for building construction activities. In this study, biomass bottom ash (BBA) was used as aluminosilicate precursor and phosphogypsum (PG) was used as a calcium source. The mixtures of BBA and PG were activated with the sodium hydroxide solution or the mixture of sodium hydroxide solution and sodium silicate hydrate solution. Alkali activated binders were investigated using X-ray powder diffraction (XRD), X-ray fluorescence (XRF) and scanning electron microscopy (SEM) test methods. The compressive strength of hardened paste and fine-grained concrete was also evaluated. After 28 days, the highest compressive strength reached 30.0 MPa&mdash, when the BBA was substituted with 15% PG and activated with NaOH solution&mdash, which is 14 MPa more than control sample. In addition, BBA fine-grained concrete samples based on BBA with 15% PG substitute activated with NaOH/Na2SiO3 solution showed higher compressive strength compered to when NaOH activator was used &minus, 15.4 MPa and 12.9 MPa respectfully. The NaOH/Na2SiO3 activator solution resulted reduced open porosity, so potentially the fine-grained concrete resistance to freeze and thaw increased.

Recently, alkali-activated materials have shown great potential for use in the construction industry. The aim of this research was to study the properties of alkali-activated clay and the effect of incorporating AlF 3 production waste from a fertilizer production plant. The AlF 3 production waste, which was rich in alumina and silica, contributed to improved mechanical behaviour for all the mixtures investigated. This demonstrated the potential for use of this waste material. It was also noted that the dosage of Na 2 O, Al 2 O 3 , and SiO 2 are significant factors that influence the binding mechanism and properties of alkali-activated clay samples. The raw materials, precursors, and alkali-activated samples were investigated by X-ray diffraction, fluorescence spectroscopy, and scanning electron microscopy. The highest compressive strength (17.50 MPa) was observed for alkali-activated clay samples containing 25% AlF 3 production waste, with an increase in compressive strength of up to 64% compared to the samples without the AlF 3 production waste. Deleterious natrite was shown to form in the samples without the production waste, which could be the reason for the lower observed mechanical properties of such samples.

In power plants biomass combustion produces large quantities of biomass bottom ash wastes. During the combustion process, the produced ashes are enriched in the radionuclides. The different enrichment of the various radionuclides within a radioactive series, such as that of 226Ra, 228Ra, 228Th, 40K, 210Pb and 137Cs results in the disturbance of radioactive secular equilibrium. The production of energy from renewable resources, such as biomass, is increasing rapidly. As the demand for bioenergy production increases, waste products from biomass combustion will increase too and will become a relevant environmental and economic problem. Therefore, environmentally friendly, and economic solutions to recycle the resulting by-products are essential. This research provides a real opportunity to save cement thus disposing the waste by using zeolitized biomass bottom ash as supplementary cementitious materials. The zeolitized products were examined by X-ray diffraction (XRD), X-ray fluorescence spectrometer (XRF) spectroscopy and high-resolution gamma spectrometry. In all investigated cases, compressive strength in hardened cement pastes and concrete samples slightly increases by replacing from 3% to 5% of Portland cement with zeolitized ashes. The results showed that natural radionuclides as 226Ra, 228Ra, 228Th, 40K are concentrated in similar way as in case of ashes obtained from combustion. However, addition of biomass leads to concentration of artificial radionuclide 137Cs that is still commonly present in biomass due to Chernobyl disaster. The observed activity concentration of 137Cs reaches the level of natural radionuclides concentration. Taking into consideration the contribution of 137Cs to gamma dose (usage of expanded activity index formula) may lead to exceeding the value of 1 in some cases. Calculated differences between activity indexes reach 13%.

This is a study of municipal solid waste (MSWI) ash from the Lithuanian incinerator, which was used as an aluminosilicate precursor and pore-forming agent for the production of porous alkali-activated materials. The relationships between the density, pore size, pore distribution, compressive strength, mineral composition, thermal conductivity, and incorporation of phosphogypsum (PG) and/or hydrogen peroxide were observed. It was found that the porous materials had density in the range of 833 kg/m3 − 1345 kg/m3, compressive strength was in the range of 1.5 MPa − 4.1 MPa and thermal conductivity varied in the range of 0.23 W/(m⋅K) − 0.39 W/(m⋅K). The additional pore forming agent hydrogen peroxide with PG has a positive effect on the formation of small pores in the alkali-activated MSWI ash system. In this case, without PG, the number of large pores increased due to coalescence. The addition of PG acted as a binding accelerator of the alkali-activated system and this resulted in the formation of a large number of small and medium sized pores. The prepared porous alkali-activated MSWI ash had the best results with the incorporation of 15% phosphogypsum. In this case, the samples had a compressive strength of 1.8 MPa, the density reached 900 kg/m3 and the thermal conductivity was 0.23 W/(m⋅K).

In the petroleum industry during a catalytic cracking process, the used zeolitic catalyst becomes waste. This article investigated the sorption capacities of ammonium ions from aqueous solutions onto the previously mentioned zeolitic waste by batch experiments. Three types of zeolitic waste were used: unmodified zeolitic waste with two different particle size distributions and H2O2-modified zeolitic waste. Several techniques, including X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET) multilayer adsorption theory measurements, and X-ray fluorescence analysis (XRF) were used to demonstrate experimentally that the zeolitic waste could be used as a sorbent for the water decontamination of NH4+ ions. The morphology of zeolitic waste investigated by scanning electron microscopy (SEM) revealed particles with a spherical shape. The nitrogen adsorption–desorption isotherms showed an isotherm mixture of types I (pure microporous) and IV (mesoporous). This suggested that the investigated zeolitic materials were mesoporous (4.84 nm) and microporous (0.852 nm), as well as containing slit/cylindric pores, according to a quench solid density functional theory (QSDFT) adsorption branch model. Zeolitic waste from the oil industry showed good NH4+ sorption properties (removal efficiency of 72%), thus becoming a potential adsorbent to be used in the treatment of contaminated aqueous effluents polluted with ammonium ions. Simultaneous waste and water decontamination can be achieved, providing a new tool and enhanced capabilities for environmental remediation.

Alkali activated binders (AAB) are potential alternative to ordinary Portland cement. The AAB is produced by activating the source of amorphous SiO2 and Al2O3 with alkali solutions (NaOH, Na2SiO3·nH2O, KOH or etc.). As a result of alkali activation the N-A-S-H gel is forming as binding phase in the structure. Influence of different SiO2/Na2O ratio to the alkali activated fly ash compressive strength, chemical composition (XRD, FTIR), crystallinity of hydroxy-sodalite (by-product of the alkali activation) and structure (SEM-EDX) was studied. The highest compressive strength for AAB was achieved with SiO2/Na2O ratio in the range of 1.5–2.3 (max. 56.16 MPa). XRD and FTIR suggest if ratio was too low, rapid sodium carbonation would take place and significantly reducing sodium content for alkali activation. On the other hand, if ratio was higher than 2.3 there would not be enough sodium, that results in low compressive strength. Also, higher SiO2/Na2O ratio reduces hydroxy-sodalite crystallinity.

Alkali-activated materials are potential alternatives for Portland cement. Their use leads to reductions in CO2 emissions and recycling of various industry by-products. These new alternative binders have a wide range of uses and high technological properties. In the research presented in this paper, the influence of additional sulphur slime powder (as accelerator) was investigated. The biomass bottom ash (BBA) was used as raw material and sodium hydroxide was used as the alkaline activator. The sulphur slime is a by-product in a fertilizer production plant. The samples were prepared with different amounts of sulphur slime; the levels of sulphur slime additive were 0%, 0.5%, 1.0%, 3.0% and 5.0% by weight in the raw material mixtures. Alkali-activated binders were mixed and conditioned at a temperature of 60 °C for 48 h, followed by curing at room temperature for 26 days. The microstructure of the material was analyzed through scanning electron microscopy (SEM) and the composition of the materials was analyzed using X-ray diffraction (XRD) and X-ray fluorescence (XRF) spectroscopy. The compressive strength of hardened alkali activated paste was measured after 28 days. In all the cases investigated, the compressive strength of hardened cement paste samples increases with the presence of Sulphur slime powder. It was found that during the hardening process sulphur reacts with sodium hydroxide forming Na2SO4, which acts as an accelerator. According to some researchers, Na2SO4 shows a significant accelerating influence in alkali-activated binder systems. The optimal amount of sulphur slime in raw materials mixtures was also evaluated., peer-reviewed

Perlite is the mineral of volcanic origin. Expanded perlite has good heat insulation and sound absorption properties. It is light, resistant to fire, moisture and micro-organisms, harmless to health. However, due to the presence of hyaline phase, its use in Portland cement mixture is problematic. In this paper, the zeolitization of expanded perlite was carried out to improve its hydraulic properties. The conversion of expanded perlite into zeolite material was carried out when Na2O : Al2O3 : SiO2 : H2O molar ratio was equal to 2: 1: 2: 10 and the suspension of starting materials was treated for 3 hours at 100?C temperature. Mechanical and physical properties of hardened cement paste containing 0%, 5%, 10%, and 15% of pure perlite admixtures, zeolitized perlite, and perlite altered to calcium (Ca2+) zeolite were researched. The results showed that zeolitization of expanded perlite activates its hydraulic properties; after 28 days of hydration under normal conditions, the compressive strength of the specimens modified with 5% of zeolitized perlite admixture was 49-50 MPa, whereas the compressive strength of the specimens containing 5% of pure perlite admixture was only 33 MPa.

Studies that are analysing new, environmentally friendly building materials are getting more attention in scientific community. This research is focused on hybrid geopolymer concrete (geopolymer with ordinary Portland-cement (OPC) additive) with aim to study strength development. In this article hybrid geopolymer concrete, manufactured using biomass bottom ash, fly ash and production waste of aluminium fluoride manufacturing (silica gel) with 4 different amounts of OPC (0%, 5%, 10% and 15%) is studied. Each blend is kept in 50 0C temperature and tested after 7, 14 and 28 days. The purpose of research was to study strength development in hybrid geopolymer concrete made from materials that are mentioned aboveDOI: http://dx.doi.org/10.5755/j01.sace.19.2.17836

It is known that the use of various industrial wastes as recycled aggregate for concrete to build environmentally sustainable structures has several practical and economic advantages. Usually such recycled aggregates consist mainly of crushed concrete and crushed asphalt pavement material. However, in this study a by-product of acid – sulphur slime is used as a partial substitute for natural fine aggregate (sand). Sulphur slime is a solid material consisting mainly of elemental orthorombic sulphur with some impurities like gypsum and anhydrite. The goal of this research is to investigate whether it is possible to manufacture concrete with sulphur slime despite the presence of elemental sulphur. Each set of samples analyzed was based on 5 different compositions with 0 %, 10 %, 20 %, 30 %, 40% Sulphur slime as a substitute of aggregate. Samples was tested for their mechanical characteristics including the compressive and flexural strength. The samples structure was analyzed with SEM and optical microscopy and the composition of the materials was analyzed through SEM and XRD. The inclusion of Sulphur slime led to a reduction in the mechanical properties of the material, related to the formation of secondary ettringite and associated expansion within the material.DOI: http://dx.doi.org/10.5755/j01.sace.19.2.17635

This paper analyses the use of two types of supplementary cementing materials, – dry sludge from waste wash water of concrete plants and zeolitic by-product – for producing hardened cement paste specimens. X-ray powder diffraction, scanning electronic microscopy, energy-dispersive X-ray spectroscopy, and thermal analysis were used as investigation methods. Test results showed that the addition of dry sludge reduced the compressive strength of hardened cement paste at both 7 and 28 days. In hardened cement paste specimens where Portland cement was substituted with 5 %–30% of dry sludge the compressive strength decreased significantly after 7 and 28 at days. After 28 days blended Portland cement containing up to 10% of supplementary cementing materials ((SCM) - dry sludge and zeolitic by-product) demonstrated higher compressive strength than the reference specimen as a result of synergistic interactions, whereas higher replacement levels led to reduction in compressive strength.

The development and assessment of alkali-activated materials has become increasingly widespread over the past few years. Alkali activation is a rapidly developing field of activity in the research society. Such a great interest of alkali activated materials resulted in a large amount of waste recycling. Provis et al. identify important needs for future research and development to support the optimal and appropriate utilization of alkali activated materials as a component of a sustainable future construction materials industry. The aim of this research was to evaluate the influence of aluminum hydroxide additive on the physical and mechanical properties of alkali-activated slag.DOI: http://dx.doi.org/10.5755/j01.sace.17.4.16731

By producing 1 ton of Portland cement clinker in environment releasing about 0.85 tons of CO2: 70% of limestone decarbanization and 30% of electricity and thermal consumption. High specific CO2 emissions results take the responsibility of Portland cement industry for about 5% of global CO2 emissions. One of the ways to reduce CO2 emissions is the use of Portland cement substituting materials. Properly treated ashes could become not a waste of biofuel but a valuable raw material for new construction materials. This paper presents results about the characterization of the biomass bottom ash sourced from the combustion of plant biomass located in Lithuania, and the study of new cement formulations incorporated with the biomass bottom ash. The study includes a comparative analysis of the phase formation, setting and of the new cement – bottom ash formulations based on these biomass bottom ash. Techniques such as X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), measurement of hydration temperature were used to determine the structure and composition of the formulations.DOI: http://dx.doi.org/10.5755/j01.sace.14.1.14893

The possibility to use by-product SiO2·nH2O (often called AlF3 production waste) in cement casting has been attracting the interest of researchers for many years, although high content of fluorine makes the use of amorphous SiO2 problematic. Finding the way of utilizing waste products is a very important research topic at the moment. In this study AlF3 production waste was investigated as the basic ingredient of a new pozzolanic material. The goal of this study is to investigate the possibilities of using AlF3 production waste, washed in ammonia solution, in cement stone specimens. Chemically treated silica gel additive was proved to reduce the amount of Ca(OH)2 and CaCO3 in hardened cement paste samples. Experimental research has revealed that the density in hydrated samples reduces from 2220 kg/m3 to 2030 kg/m3 with the increase of silica gel content from 0 % to 35 %. The compressive strength of samples containing 10 % of silica gel additive increased by 8.04 % compared to the samples without the additive. SiO2 additive used at 10 % and 20 % increased the maximum hydration temperature. In this case, the additive modifies the hydration kinetics.DOI: http://dx.doi.org/10.5755/j01.ms.18.2.1925

The synthetic zeolite Y (Na 56 [(AlO 2 ) 56 (SiO 2 ) 136 ]×250H 2 O) is used as an adsorbent for petroleum refining during catalytic cracking, and after a certain time it contaminates and becomes a waste. This waste in Lithuania can make up to 200 tons per year. The EU environmental requirements are becoming stricter, and it is necessary to create the retired absorbent processing methods for the further rational use in manufacturing various products and materials. The waste in this research was activated by integrating in 15 % H 2 O 2 aqueous solution, using 20 kHz ultrasonic processing of 200 W powers. Gas-vapor bubbles are formed in the suspension after the treatment with ultrasound. The temperature inside increases to several thousand degrees and the pressure to thousands of atmospheres. Shock waves appear after the collapse of bubbles. The process in the fluid during cavitation helps crushing zeolite particles, facilitates the separation of impurities and accelerates their oxidation reaction. The zeolite sorption capability increases after treatment with ultrasound, especially using ultrasonic treatment in a hydrogen peroxide solution. In this case, the sorption capacity increases about 2.18 times. Thus, the investigated zeolite waste can be used in environmental protection programs for heavy metal sorption. DOI: http://dx.doi.org/10.5755/j01.ct.66.1.13384

The synthesis of zeolite NaA from silica by-product was carried out in the presence of 20 kHz ultrasound at room temperature. Zeolites obtained in this type of synthesis were compared to zeolites obtained by performing conventional static syntheses under similar conditions. The sonication effects on zeolite NaA synthesis were characterized by phase identification, crystallinity etc. The effects of different parameters such as crystallization time and initial materials preparation methods on the crystallinity and morphology of the synthesized zeolites were investigated. The final products were characterized by XRD and FT-IR. It was possible to obtain crystalline zeolite NaA from by-product silica in the presence of ultrasound.

Effects of the natural zeolite clinoptilolite (Na, K, Ca) 2-3 Al 3 (Al, Si) 2 Si 13 O 36 ·12H 2 O on the mechanical properties and strength of Portland cement paste, mortar, and concrete samples were investigated. Incorporation of 0; 5; 7 and 10 % (by weight) of the clinoptilolite in Portland cement paste (W/C = 0.38), mortar specimens using the water-solid ratio (W/C = 0.44) and concrete mixture specimens (W/C = 0.57) were cured at room temperature for 3, 7, 14 and 28 days. The mechanical properties were determined by measuring the bending and compressive strength of the hardened specimens of mixtures. The hydration products of Portland cement mixture specimens were analysed by using an X-ray diffractometer (XRD), the natural zeolite clinoptilolite with a differential thermal analysis DTA and thermogravimetric analysis (TGA). In the examined conditions after 28 days of hydration hardened cement paste samples with 10 % of the natural zeolite replacement had the highest compressive strength. It can be assumed that the natural zeolite ( clinoptilolite) pozzolanic properties are not immediate , but its apparent after 28 days of hydration . The bending and compressive strength of mortar samples does not depend on the zeolite replacement content. By using the natural zeolite ( clinoptilolite) the economic effect can be achieved because in concretes up to 5 % of clinoptilolite can be replaced the cement without changing mechanical properties of concrete products . DOI: http://dx.doi.org/10.5755/j01.ct.64.2.6023

Wood-cement materials are widely produced and applied in many developed countries. In this case special prepared wood aggregates are employed. Wood sawdust practically is not employed.Extracts, present in wood, slow down the cement hydration. The influence of mineral additives on this process was determined. The efficiency of mineral additives depends on their hydraulic activity.It has been found that the mineral components (additives) of sawdust concrete have a positive effect on cement setting and hardening due to two reasons: 1) hydraulic and other mineral additives absorb wood extracts from liquid phase which inhibit and retard setting of cement and reduce their concentration in solution; 2) reduce pH of liquid phase so the hemicellulose which is in sawdust or other wood aggregates, less disintegrate lightly soluable sugars.When sawdust amounts are different, the optimum cement and rottenstone relation is not constant:y= 1,29x−0,66, whereyis cement and rottenstone mass relation,x is sawdust and binding material (cement+rottenstone) volume relation.The influence of sawdust concrete humidity on its strength was found: whereyis concrete compressive strength (MPa), when its humidityX(%),Ris concrete compressive strength (MPa), when its humidityW(%).The possibility of accelerating the hardening process of concrete mixes of cement-rottenstone (gaize)-sawdust system by means of steaming at 80 °C was studied, too. It is impossible when producing ordinary wood-cement materials.The physical and technical properties of sawdust concrete such as shrinkage strain, expansion deformations and elastic modulus were determined.Sawdust concrete contraction deformation depending on concrete density may vary by 8…14 mm/m and expansion (in humid conditions) by 1,1…2,5 mm/m. Deformation decreases when quartz sand additive is used. When the concrete gets dry repeatedly, deformations are smaller.The sawdust concrete elasticity modulus is similar to that of light concrete with inorganic additives having the same density.Its frost resistance depends on the concrete structure and cement quantity. When the concrete with a small amount of sawdust is used (cement+additive: sawdust = 5:1), the samples endure 75 freezing cycles.The heat conductivity of sawdust concrete is low.The experimental data have shown that structural thermoinsulated small blocks can be produced from these concrete mixes. Article in Lithuanian. First Published Online: 26 Jul 2012