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This paper describes a programme of experimental measurements performed in support of a parallel programme of field investigations to evaluate the construction methods used at the site of the ancient city of Nippur. The experimental programme investigated both the mechanical properties and durability of the ancient clay masonry units used in the construction of buildings at Nippur including tests for dimensional consistency and flatness, density, compressive strength, initial rate of water absorption and thermal properties. The test results have been compared with those for modern brick units available nowadays in Iraq and with hard natural stone samples.The field investigations showed that the important buildings were constructed using composite walls inclusion firing clay masonry units with two nominal dimensions (30× 30×7) cm and (30× 15× 7) cm (l, w and h). The formulation of working design technique was followed to achieve the member stability under applied loads. Layers of bitumen material were used as a binder for both bed and head joints in order to provide the desired strength level for the masonry wall. The experimental results show that the ancient brick units and stone samples exceed the tolerance and range of dimensions limits recommended by current EN Standards. Lower density values were recorded for the ancient brick units compared with that for both modern clay brick and stone specimens and these values showed agreement with the modern classification of high density (HD) units. Approximately similar values of compressive strength were observed for both ancient brick units and natural stone samples reaching about 17 MPa, whilst modern clay brick samples showed lower compressive strength value suitable for application of partition walls. The initial rate of water absorption increases with an increase of the soaking time, but tends to decrease after 90 minutes for both ancient and modern brick units. Superior performance in terms of thermal conductivity, thermal resistance and durability under fire action were observed for the ancient brick samples compared with modern clay brick and stone samples.

This paper reports a study based upon experimental investigation which aims to assess the behaviour of reinforced concrete columns strengthened with a new configuration of steel wire mesh as part of ferrocement layer under the action of axial compression loads. Square and circular small scale columns with three different slenderness ratios of 5, 6.7 and 10 were adopted. A comprehensive experimental progarmme was then running to measure the load capacity and both lateral and vertical displacements. The failure mode was also monitored for each tested case. The results obtained was compared with the reference column samples (without wire mesh) and with some expressions suggested by ACI Code. The experimental results showed that the most influential parameter on the property of load carrying capacity is the slenderness of column. As the slenderness increases, the load capacity clearly decreases. The use of wire mesh enhanced the capability of column to resist the axial loads due to confinement role provided by such material. The maximum percentage increase in load carrying capacity for the modified columns compared with those for the reference samples was 53% for the circular column at slenderness ratio of 10. The critical path of the failure mode was similar for all of the tested columns and normally began from the top or bottom ends, then, in some cases, passed through the middle zone of the column. A suitable expression was suggested to be used for calculating the modulus of elasticity of the tested column based upon the value of load carrying capacity under compression loads.

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