Durability of traditional plasters with respect to blast furnace slag-based plaster

Use of FGD gypsum in fire resistant panels

“…Some of them were immersed in water (reference samples) and the others were immersed in a 1 N sulphuric acid solution (the test procedure is explained in detail elsewhere (Cerulli et al, 2003). After 14 days, the residual mechanical resistance of the corroded samples was measured and compared with the reference samples (each value is an average of two measurements).…”

“…This is probably due to the dependence of acid resistance on the presence of calcium carbonate among other reasons (Cerulli et al, 2003). A high amount of calcium carbonate is deleterious for the R A of gypsum.…”

Ageing of lime mortars with admixtures: Durability and strength assessment

“…The extent to which a mortar is affected by these deterioration factors is a function of the mortar's properties, which depend, in turn, on several issues, such as the kind and characteristics of the binder and the aggregate, the binder/aggregate ratio, the amount of mixing water, the mortar's permeability [9][10][11][12], the water absorption capacity through capillarity [10,13], water intake [7,14,15], the presence of admixtures and the curing conditions [16][17][18]. SO 2 exposure is supposed to affect the mortars because gaseous SO 2 has been widely reported to react with calcium carbonate, giving rise to the formation of both calcium sulphite hemihydrate (CaSO 3 .1/2H 2 O) and calcium sulphate dihydrate (CaSO 4 ·2H 2 O) on the mortar's surfaces [6,8,[19][20][21].…”

“…The water retaining products were added as they are supposed to improve the homogeneity of the mixture, enhancing the workability of the mortar and some of the properties in the hardened state [1,8]. Two different commercial water-retaining agents were used: hydroxypropyl methylcellulose, widely used in cement mortars, and a guar gum derivative (hydroxypropylguar), which is used in dietetics and pharmacy due to its high water retention capacity, although its potential as admixture for mortars has received scant attention [10,11]. Finally, the rationale for the use of a starch derivative is that its water-reducing action could be desirable in lime-based mortars to avoid large amounts of mixing water that could slow down the carbonation process.…”

Weathering effects on physical–chemical properties of external plaster mortars exposed to different environments

“…Resistance tests on microclimate is one of the ageing tests group. The second group concerns the effect tests of material additives on physical and mechanical properties and durability, including mortars and plasters [7,17,20,28,29,32]. As a result, characteristics of tested materials are obtained, which can have two general uses.…”