The paper is focused on the research of ecotoxicological properties of mortar prisms produced with partial cement replacement by ash from energy recovery of municipal waste. Two types of ash were used: ash from incineration and ash from municipal waste gasifi cation. According to the Waste Catalogue, ash is considered other waste, which is non-hazardous and nowadays it is predominantly landfi lled. Negative results of standardized biotests are inevitable precondition for the use of ash for construction products. The results from both biotests (acute toxicity test on aquatic organisms Daphnia magna and growth inhibition test of higher cultivated plants Sinapis alba) confi rmed suitability of cement replacement by ash from energy recovery of municipal waste. Environmental safety of produced mortar prisms is different. Recommended replacement of cement with ash, obtained from municipal waste gasifi cation, is 10% and with ash gained from incineration is 15%. The use of this type of waste in construction industry will lead to the decrease of landfi lled waste. Due to the replacement of cement with waste (from industrial branches) natural resources of raw materials used in the process of cement production are saved.

Bamboo Ash is a safer and more sustainable building material. It is possible to use bamboo ash as a partial cement replacement as an alternative to cement application and also to reduce pollution. For this study, the main purpose is to determine the compressive strength and water absorption of cement sand brick containing bamboo ash. Laboratory tests such as compression tests and water absorption tests on cement sand brick with bamboo ash as a partial replacement for cement have been conducted. The mixes with various ratios using bamboo ash are 5%, 7%, and 10%. The specimen size for cement sand brick is 215 mm long, 102.5 mm wide, and 65 mm deep according to BS3921:1985. The results from the specimens containing Bamboo Ash have been compared to the control specimens. The water absorption test results increase as the percentage of Bamboo Ash increases due to particle size and air void, but the compressive strength decreases at 28 days.