Strength and Durability of Mortar Using Cork Waste Ash as Cement Replacement

Abstract

Cork powder, the major waste from cork processing industries, is generated from grinding, cutting and finishing operations throughout the industrial cork process. Cork powder has been used mainly as fuel in cork industries. Cork waste ash is usually landfilled but if efficiently used in cement based construction materials it could contribute to sustainability. Strength and durability testing was undergone on mortar with 10 and 20% cement replacement with cork waste ash. Although strength is acceptable for 10% cement replacement with cork ash (5% loss at 90 days, compared to control), most durability properties (tested up to 6 months according to test type) reduced performance probably due to a broader pore structure caused by coarse particles in the ash which tested non pozzolanic. Moreover, cork waste ash does not present the necessary requirements in terms of chemical properties considering several standards. Present work has revealed that this cork waste cannot be used as a pozzolan or as a filler in cement based materials. In fact it is known that chemical composition of biomass ash is highly variable due to moisture variations, ash yield and different genetic types of inorganic matter in biomass and therefore it is important to pinpoint which types of biomass waste are adequate or not to use as cement replacement in construction.

Quality and durability properties and life-cycle assessment of high volume biomass fly ash mortar

“…Mortars with pozzolanas had a higher consumption of CH and this led to a decrease in the alkalinity of mortar. The decrease in the alkalinity is one of the conditioning parameters for the development of the carbonation reaction [23,57].…”

Plant biomass ashes in cement-based building materials. Feasibility as eco-efficient structural mortars and grouts

“…Around 20% to 30% of the raw cork received at the processing units is discarded, mainly as cork dust [59]. That cork powder is generated from grinding, cutting and finishing operations throughout the industrial cork process [60]. Cork waste ash is the result of cork industries where the cork powder is used mainly as fuel [60].…”

“…That cork powder is generated from grinding, cutting and finishing operations throughout the industrial cork process [60]. Cork waste ash is the result of cork industries where the cork powder is used mainly as fuel [60]. The CWA is generally deposited in landfills, increasing pollution [60].…”

Cork as a sustainable carbon source for nature-based solutions treating hydroponic wastewaters – Preliminary batch studies

“…Cork by-product is generated from several operations of wine industry and it is considered as a natural, renewable, biodegradable raw material (Olivella et al, 2011a;Ramos et al, 2014;Boschmonart, 2011). The cork oak trees are planted, the bark is stripped for the first time when tree is 20 to 25 years old; the next stripping are carried out every 9 to 12 years (Boschmonart, 2011), with an expected productive life from 150 to 300 years depending on the tree's health.…”