PSI - Issue 13

Talah Aissa et al. / Procedia Structural Integrity 13 (2018) 218–221 Talah Aissa / StructuralIntegrity Procedia 00 (2018) 000–000

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wastes under aggressive and normal curing regimes. It is now well established that the evaluation of the performance of a concrete mix is not limited to the determination of its mechanical properties since it is of paramount importance to characterize the material in terms of the parameters that rate its durability; [L.Basheer et al (2001)]. The higher amount of pharmaceutical wastes additive the longer the setting times and the lower the strength of the specimens for different curing peri o ds [Corinaldesi V et al (2010)]. The effects of using pharmaceutical wastes as partial replacement of cement on the mechanical properties of concrete were investigated. Test results indicated that the optimize amount of pharmaceutical wastes as replacement by weight of cement had the best compressive and flexural strengths; [A.Ergun et al (2011)]. 2. Materials The materials used in this investigation were Portland cement, pharmaceutical wastes, aggregate, and water. Portland cement (CPA-CEM-I / A 42.5) conforming to the Algerian standard NA 443 and pharmaceutical wastes are utilized as cementitious materials. Crushed limestone coarse aggregates with a nominal size of 16 mm, and a specific gravity of 2.70, and natural sand with a specific gravity of 2.60, were used for the concrete samples. The size grain, the fineness modulus (FM = 3.2), the sand equivalent value (SEV= 97%) and shock resistance (SR=33%) show that gravel and sand can be used in developing a high-performance concrete (HPC). 3. Formulation, mixtures, specimens and curing procedures Two types of concrete were studied: reference concrete (RC) and high-performance concrete with pharmaceutical wastes (HPCPW). The prepared specimens were stored for one year in an environment containing 5% calcium chloride, (media 1) and drinking water (media 2). In order to investigate the pharmaceutical wastes (PW) on the performance properties of concrete, two different concrete mixes were employed, details of which are given in Table 1 . Table 1. Mixture proportions and properties of concrete.

items

RC

HPCPW

W/C

0.50 400 0 200 780 170 850 2.2 12 2470

0.50 370 30 200 780 170 85 1.6 10 2510

Cement

(kg/m 3 ) (kg/m 3 ) (kg/m 3 ) (kg/m 3 ) (kg/m 3 ) (kg/m 3 )

PW

Water Sand

Gravel 3/8 Gravel 816

Air

(%) (cm)

Slump Density

(kg/m 3 )

The control mix contained only Portland cement as the binder. In the high-performance concrete with PW, Portland cement was partially replaced with, respectively, 10% PW (by weight) obtained by optimization. All concretes were mixed in accordance with ASTM C192 standard in a power-driven revolving pan mixer. Concrete cubes of 280x70x70 mm in size, and cylinders of dimensions 160Ø x320 mm were cast in steel moulds for the study of the compressive strengths, rapid chloride permeability test, and oxygen permeability test, respectively. All specimens were cast and compacted by a vibrating table. After casting, the moulded specimens were covered with a plastic sheet and left in the casting room for 24 hours. They were then demoulded and divided into two equal groups and cured under the following conditions: in the first curing condition, the specimens were immersed in water until the age of testing, while in the second curing condition, those were immersed in aggressive water (5% CaCl 2 ) until the age of testing. To ensure a concentration of chlorides constant throughout the tests, the solution in the tanks was regularly checked once a week and changed if the difference between the concentration of the solution and the initial concentration exceeded 5%. The main tests carried out on the fresh concrete are the workability (slump test), the percentage of air contents determined by the aerometer and the density. The effect of using PW on hardened concrete properties at different ages (28, 90,180,365 days) was studied. The results of these tests are given in Table 1.