The study investigates effect of the additive consisting of natural zeolite (clinoptilolite) and soda lime glass powder on the hydration, mechanical properties and porosity of Portland cement concrete. The effect of mineral additive on the technological, physical-mechanical properties and porosity of the mortar was investigated by increasing the content of natural zeolite and glass powder added to the mortar up to 20% by weight of cement in increments of 5% and different particles size of natural zeolite. The mixes with the best technological and mechanical properties were identified and further studies were conducted by replacing 10% and 15% of cement with natural zeolite and soda lime glass with an average grain size of 59.3 μm, 29.0 μm or 3.6 μm of zeolite, and 29.6 μm of glass powder. The hydration process and microstructure of hardened cement paste modified with the aforementioned mineral additives was analysed by microcalorimetry, X-ray diffraction tests and thermogravimetric analysis. The optimal composition of cement paste and particle size distribution of natural zeolite were determined to achieve the higher flexural and compressive strength and lower open porosity. The mixture of mineral additives has the highest effect in terms of flexural and compressive strength and open porosity when added at the proportion 75:15:10 (cement:natural zeolite:soda lime glass) and when zeolite with an average particle size of about 3.6 μm is used

The application of natural zeolite clinoptilolite (Si/Al = 5.8) for substituting up to 20 vol. % of the cement (in mortars) was studied. The effect of the natural zeolite on the consistency and compressive strength at 7, 28 and 90 days was tested at different dosages of clinoptilolite in the mixture. The optimal content (15 % by volume) of the active mineral addition was selected according to the achieved strength results of the mixture and the effect of natural zeolite on the early and late cement hydration was studied. The results of Chapelle test for pozzolanic activity, the initial and final setting times of the paste, thermogravimetric analysis and X-ray diffraction analysis of hardened cement paste showed that natural zeolite clinoptilolite accelerates early and late hydration of cement. No significant differences in calcium hydroxide (CH) content between the specimens modified with clinoptilolite and the specimens containing only ordinary Portland cement (OPC) were observed, despite the high pozzolanic activity of the zeolite.

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Tyrimo tikslas – nustatyti buitinių atliekų naudojimo perspektyvas Lietuvoje, prognozuojant buitinių atliekų susidarymo tempus, surinkimą ir analizuojant jų deginimo galimybes energijai gaminti, vadovaujantis ekonominiais, ekologiniais ir socialiniais kriterijais. Ekonominis vertinimas atliekamas pagal 3 kriterijus: 1) šiukšlių deginimo stoties technologinė kaina, Lt/kW; 2) investicijos, generuojamos energijos vienetui, Lt/MWh; 3) išlaidos dujoms tokiam pačiam kiekiui energijos pagaminti, Lt. Ekologinis įvertinimas atliekamas pagal sudeginto kuro kiekio ir išsiskyrusių teršalų santykį. Socialinis vertinimas atliekamas gyventojų apklausos būdu. Įdiegus Lietuvoje šiukšlių deginimo stotis per 25 metus būtų galima sudeginti 20,63 mln. tonų šiukšlių ir pagaminti 4756 GWh elektros ir 16223 GWh šilumos energijos.