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This paper presents the details of experimental testing of soil, adobe masonry units, and assemblages for the first time in Pakistan. Adobe units were tested both in compression and bending. The compressive strength of adobe masonry was determined by experimentally testing masonry prisms and wallettes, whereas diagonal compression wallettes were tested for determining shear strength. Five and three specimens were used, respectively, for compression and shear strength testing, and an average of these was used as a representative of a particular mechanical property. A soil sample was tested for classification and particle size distribution, which showed that it contained 96% silt and clay contents, which were higher as compared to the soil used for adobe structures in other parts of the world. Both adobe units and soil mortar presented shrinkage cracks upon drying. The compressive strength of adobe units complied with the requirements of international codes despite very high silt and clay contents in the employed soil. The compressive strength of the prism was higher compared to the wallette. The elastic moduli of the adobe masonry prism and wallette were found to be 113 and 114 MPa, respectively. Although the adobe masonry shear strength was comparable to the shear strength reported in the existing literature, its modulus of rigidity was considerably small. The presented data in this paper are essential for improving the built environment in Pakistan. [ABSTRACT FROM AUTHOR]

Two Pakistani volcanic ashes, VA1 (as is and calcined) and VA2 (as is), were incorporated into mortar cubes, concrete cylinders, and concrete beams as a partial substitute for ordinary Portland cement (OPC), and were studied in detail. The X-ray diffraction patterns showed that both ashes possessed crystalline as well as amorphous phases. The pozzolanic activity index (PAI) of VA1 at 7 d was below 75%, whereas it was 80% at 28 d. The pozzolonic activity indices in OPC mortars containing VA2 were much higher than those for VA1, both at 7 and 28 d. In mortar cubes and concrete cylinders, approximately the same compressive strengths were observed in samples containing 100% cement as in those incorporating a 10% replacement of cement by either VA1 or VA2. Mortar cubes soaked in 5% sodium sulphate solution demonstrated consistently improved resistances to sulphate attack as ash content increased in the mortar. Similar results were also observed in water absorption tests. Modulus of rupture of all concrete beams decreased as the levels of VA1 and VA2 increased from 10% of OPC content to 40%. Rupture moduli were higher for VA1 than for VA2 at all cement replacement levels. Deux cendres volcaniques du Pakistan, VA1 (telle quelle et calcinée) et VA2 (telle quelle) ont été incorporées dans des cubes de mortier, des cylindres de béton et des poutres de béton comme substitut partiel du ciment Portland ordinaire (« OPC ») et ont été étudiées en détail. Les patrons de diffraction des rayons X ont montré que les deux cendres présentaient des phases cristallines et amorphes. L’index de réactivité pouzzolanique (« PAI ») de VA1 à 7 jours était inférieur à 75 %, alors qu’il était de 80 % à 28 jours. Les « PAI » des mortiers « OPC » contenant des cendres VA2 étaient de beaucoup supérieurs à ceux des cendres VA1 à 7 et à 28 jours. Environ les mêmes résistances en compression ont été observées dans les cubes de mortiers et dans les cylindres de béton contenant 100 % de ciment que dans ceux comprenant 10 % de substitution par des VA1 ou des VA2. Les cubes de mortier trempés dans une solution à 5 % de sulfate de sodium ont démontré des résistances améliorées de façon uniforme à l’attaque des sulfates lorsque le contenu en cendres augmentait dans le mortier. Des résultats similaires ont été observés dans les essais d’absorption d’eau. Le module de rupture de toutes les poutres en béton a diminué avec l’augmentation des niveaux de VA1 et de VA2 de 10 % à 40 % dans les OPC. Les modules de rupture des VA1 étaient supérieurs à ceux des VA2 à tous les niveaux de substitution dans le ciment. [ABSTRACT FROM AUTHOR]