Structural design deeply involves material strengths, which are obviously affected by uncertainty. As far as the material “concrete” is concerned, building codes (Italian codes, Eurocodes, ACI regulations) typically state that it should be identified and classified by means of its conventional characteristic uniaxial compressive cubic strength at 28 days. Although the fundamental importance of ...

Ultrasonic pulse velocity technique is one of the most popular non-destructive techniques used in the assessment of concrete properties. However, it is very difficult to accurately evaluate the concrete compressive strength with this method since the ultrasonic pulse velocity values are affected by a number of factors, which do not necessarily influence the concrete compressive strength in the ...

Currently, building industry uses non-destructive testing methods primarily for evaluation of concrete quality. Efficiency of ultrasonic pulse method (UPM) was proved in order to determine compressive strength of solid bricks (concrete, calcium silicate and burnt ones). Parameters obtained from UPM testing (such as ultrasonic pulse velocity, dynamic modulus of elasticity) are affected by shape/...

Today concrete is most widely used construction material due to its good compressive strengt h and durability. Depending upon the nature of work the cement, fine aggregate, coarse aggregate and water are mixed in specific proportions to produce plain concrete. Plain concrete needs congenial atmosphere by providing moisture for a minimum period of 28 days for good hydration and to attain desired...

The granite stone is the most widely used in the construction and granite slurry is generated through cutting and polishing of the stone. Granite slurry is waste material consisting of very fine powder and creats disposal and environmental problems in worldwide today. Disposal of granite waste leads to health hazards like respiratory and allergy problems to the people around. It also causes the...

Earth-moist concrete mixes are the starting substance for the mass production of concrete products like pipes, slabs, pavement stones and curb stones. The working properties of earth-moist concrete (EMC), caused by its dry consistency, are advantageous. So, in comparison to normal-weight concrete, the consistency of EMC allows for direct stripping of concrete products after filling and vibratin...

This study introduces, two models based on Gene Expression Programming (GEP) to predict compressive strength of high strength concrete (HSC). Composition of HSC was assumed simplified, as a mixture of six components (cement, silica fume, super-plastisizer, water, fine aggregate and coarse aggregate). The 28-day compressive strength value was considered the target of the prediction.  Data on 159...

Results of experimental investigation carried out to study the effects of addition of natural san fibres on the fracture toughness and impact strength of high-volume fly ash concrete are presented in this paper. San fibres belong to the category of ‘Natural Bast Fibres’, also known as ‘Sunn Hemp’. Its scientific (botanical) name is Crotalaria Juncea. It is mostly grown in the Indian Sub-Contine...

The high performance concrete is a highly complex material that consists of cement, water, blast furnace slag, super-plasticizer, coarse and fine aggregate. All of the materials play a certain role in the compressive strength of concrete. Combined with the information about age, the compressive strength of concrete is determined by eight attributes: 1. Cement (kg/m!) 2. Fly ash (kg/m!) 3. Blast...

Nano materials have been widely used in laboratory and industrial scales in order to improve various properties of concrete and concrete mixture. The mainstream practice of the researches in this field is to add metallic nano-particles into the concrete mixture. The present research focuses on adding Micro-Nano Air Bubbles (MNAB) into water before mixing it with aggregate and cement mixtures. I...