The paper deals with corrosion resistance of cement mortars with various amounts of ground granulated blast-furnace slag (GGBS). The mortars were tested in the environment containing acids and sulphates corresponding to the aggressive factors acting on concrete in agricultural areas. The strength development of the composites with GGBS is slower; however, the losses in their strength and mass, as well as linear changes, after storing in the aggressive environment, are lesser than for those containing only Portland cement. This can be attributed, most likely, to the favourable changes in the hardened paste microstructure, caused by GGBS presence. The addition makes the structure of the hardened cement paste more compacted, diminishing the porosity and improving the tightness The long-term tests confirm that cement composites containing GGBS can be rational substitutes for ordinary cement concrete in the aforementioned field. However, the subject of the presented research were mortars; the conclusion shall be verified by concrete testing, planned as the next step of the project.

Natural fiber reinforced bio-composites are taking a big role in various sections around the world such as industry, construction, and health section. In this study, a bio-composite material based on wheat starch matrix and natural wheat fibers is prepared. Five different specimens with following fiber contents 50,54.5,58.3,61.5, and 64.2% by weight are added to wheat starch matrix. Mechanical and physical tests are performed for different fiber weight contents. Charpy impact test results showed that impact energy is decreasing with increase in fiber content. Three-point deflection test data show that as higher fiber content as higher flexural stress is obtained. Shore D hardness test results show that the hardness values increase as fiber content increase. Water uptake test results showed that water absorption also decreases by increasing fiber content. An optical investigation is performed to calculate the average length and width of chopped fibers used as reinforcement. The average length and width of fibers were found to be 5.73mm and the average width is 0.38mm.

The paper deals with the influence of addition of ground granulated blast-furnace slag (GGBS) on the frost resistance of concrete. GGBS is a valuable modifier of concrete, having the latent hydraulic properties and particularly improving the chemical resistance of concrete. However, the performance of concretes with blast-furnace slag under freezing and thawing action is still not explained fully and remains a subject to discussion. The authors have investigated the concretes containing various amounts of GGBS and the portland cement CEM I, with various values of water to binder ratio, with and without the use of air-entraining admixture. The results of research show that the addition of blast-furnace slag causes some worsening of the frost resistance of concrete. The extent of this worsening depends on the water to binder ratio and the aeration of the concrete. However, even under the least favourable conditions, the concretes with GGBS addition have met the requirements of frost resistance after 200 cycles of freezing and thawing, given in the Standard PN-B-06265.

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In this work sol-gel method used for preparing nanoscale iron oxide ferrites dopant by copper and lithium, which carries the chemical formula Li 1-x Cu x Fe 5 O 8 where x is the added ratio as molar ratio (x = 0,0.1,0.2,0.3,0.4,0.5,0.6 and 1), during the self-combustion for sol-gel which happen at temperature of 200 o C, after that the samples were divided into four groups , the first group namely that have not been annealed while the other groups ; the second, third and fourth were annealed at 500 o C , 700 o C and 900 o C respectively. In this work the crystalline structure have a dominate phases which have been studied by using the X-ray diffraction as well as