Non-destructive testing on old masonry wall of non-pareille Manor House, South Africa

Abstract

This research investigates the mechanical properties of the old masonry gable wall of the 196-year-old Non-Pareille Manor House, an excellent example of Cape Dutch architecture. The manor house is classified as a Grade 1 heritage resource by SAHRA, the highest level of significance in South African heritage. The mechanical properties of the front gable wall of the Non-Pareille manor house have been determined through non-destructive testing. The testing methods used in this research are rebound hammer testing and ultrasonic pulse velocity testing. The surface level compressive strength has been determined through rebound hammer testing, following calibration through site sample crushing in a laboratory. Poisson’s ratio and Young’s Modulus for the masonry have been calculated from ultrasonic pulse velocity test results. From visual inspection, severe cracking above the door opening has been noted and remediation is recommended to avoid further crack opening. The compressive strength distribution indicates a higher strength at the center wall panel, with a higher Young's modulus and a lower Poisson's ratio. Increased cracking has been noted on the right wall panel, corresponding with a lower compressive strength, Young's modulus, and a higher Poisson ratio. The study achieves results through the development of a testing methodology that is unique in the field of the conservation of heritage structures in South Africa. The method can be further incorporated into other heritage structures in South Africa to sufficiently describe the mechanical properties and aid in the development of suitable conservation plans.