Giorgio Torraca (left), conservation scientist, and Giacomo Chiari (right), GCI chief scientist, test the injectability device at the GCI Building Materials Laboratory. Photo: Leslie Rainer.

Conservators and scientists from the Getty Conservation Institute are working with wall paintings conservators from the Herculaneum Conservation Project to evaluate grouts used for conservation of plasters and wall paintings at Herculaneum. Photo: Leslie Rainer.

Wall paintings such as this one at the archaeological site of Herculaneum require injection grouting to reattach delaminated plaster to the support in order to preserve them in situ. Photo: Leslie Rainer.

Beril Bicer-Simsir (left) assistant scientist, and Giorgio Torraca (right), conservation scientist testing the injectability device, which assesses the degree of ease with which a grout can be injected through a column of crushed brick, travertine, or sand. Photo: Leslie Rainer.

David Carson (left) GCI laboratory manager, and Beril Bicer-Simsir (right), assistant scientist, sieving crushed brick to be used in the custom-mixed grouts for laboratory testing. Photo: Leslie Rainer.

Beril Bicer-Simsir, assistant scientist, preparing grout samples for laboratory testing. Photo: Benedicte Palazzo.

The Vicat instrument. The Vicat instument is used to measure time of initial setting of the grouts in the laboratory. Setting is the onset of rigidity in fresh grout. Photo: Beril Bicer-Simsir.

The tensile strength of a grout is estimated through an indirect tensile test called splitting tensile test (Brazilian Test). The test is carried out on cylinders with an aspect ratio of 1:2 and tested on its side in diametral compression. Photo: Beril Bicer-Simsir.

Half-filled injection columns are used to determine the ability of grouts to pass through a capillary network of varying porous media under the effect of gravitational force. Grout is poured from the top of the half filled column and the time needed to penetrate 50 mm, 100 mm and 150 mm is recorded. Photo: Traci Lucero.

Commercial and custom-mixed grouts are undergoing a series of tests, such as this one to determine water vapor permeability, to assess the working properties and performance characteristics of different grout formulations. Photo: Hande Cesmeli.

GCI graduate intern Hande Cesmeli, weighing grout samples for water vapor permeability testing. Photo: Beril Bicer-Simsir.

Shrinkage is measured on a number of commercial and custom mixed grouts in the laboratory. Photo: Hande Cesmeli

Conservators and scientists working together to test grouts in the field at the archaeological site of Herculaneum. Photo: Leslie Rainer.

Conservators and scientists from the GCI and the Herculaneum Conservation Project carrying out field testing of laser speckle interferometry—a nondestructive technique to detect voids behind the surface of wall paintings—at the archaeological site of Herculaneum. Photo: Giacomo Chiari.

Since 2006, the grouts project team has provided informal lectures and laboratory exercises for students of the UCLA/Getty Master's Program in the Conservation of Ethnographic and Archaeological Materials. Photo: Leslie Rainer.