The properties of hydraulic mortars were studied by means of simultaneous thermal analysis (STA), according to a procedure
proposed in the literature. Hydraulic limes, cement and/or slaked lime were mixed using different proportions of both inert
and reactive aggregates, in order to test the effectiveness of such procedure in distinguishing the different degree of hydraulicity
of such samples. The use of the normalized coordinates suggested in the literature results in overlapping of the clusters
of different kinds of mortars. Modified coordinates are proposed, which give promising results in view of outlining a ‘master
curve’ of hydraulicity.
Authors:R. Lawrence, T. Mays, P. Walker, and D. D’Ayala
A high speed method of thermal
analysis was developed to allow the carbonation profile of lime mortars to
be followed within a convenient time-frame. The loss in mass on heating, up
to 700C, of lime/sand mixtures of different proportions was related to
the known quantity of lime in each mixture. It was shown that a heating rate
of 50C min–1 produced data which had
a very high correlation with known quantities of Ca(OH)2.
Thismethod can be used to measure the extent of carbonation at varying depths
through a limemortar. This can be repeated at intervals to give an insight
into the shape and extent of the carbonation front as it develops over time.
Authors:Andreas Iordanidis, Javier Garcia-Guinea, Aggeliki Strati, Amalia Gkimourtzina, and Androniki Papoulidou
study and are represented in Table 3 . Lime mortars have been classified as having CO 2 /H 2 O ratio >10, while hydrauliclime mortars have CO 2 /H 2 O values between 4 and 10 and pozzolanic mortars have values <3 [ 3 , 22 ]. According to Cardiano et
DTA/TG/DTG thermoanalytical investigation and X-ray diffractometry were carried out on hydraulic lime pastes obtained by mixtures
of thermally activated red earth with lime. Hydration reactions proceed properly mostly due to the high silica and alumina
content. In a long period of curing the paste presents calcium silicates hydrate in high quantities while there are moderate
quantities of calcium monocarboaluminate hydrate, ettringite and gehelenite hydrated. In presence of chloride, pastes lead,
after few days, a sensible acceleration of the hydration with the formation of calcium silicate hydrate and calcium chloroaluminate
hydrate. The total amount of neo-formed hydrate products in the hardened paste, indicate a development of the solidifying/stabilizing
capacity of the hydraulic binder.
of the Byzantine mortars which were mainly based on hydrauliclime or hydrated lime and pozzolanic materials as brick dust and pozzolana were well chosen by the size dimension of the aggregates according to the dimension of the joint, so that in the