The core purpose is to introduce self-healing mechanism particularly to constructions which are very liable to damage. To heal cracks in the concrete, Jonkers chose bacteria (Bacillus pseudoﬁrmus and B. cohnii), that are able to produce limestone on a biological basis. The positive side-effect of this property: the bacteria consume oxygen, which in turn prevents the internal cor-rosion of reinforced concrete. However, the bacteria do not pose a risk to human health, since they can only survive under the alkaline conditions inside the concrete. Based on these findings, Jonkers and his team of researchers developed three differ-ent
Ceramics and cements are the best examples of brittle fracture. Ductile fracture is better than brittle fracture, because ductile fracture occurs over a period of time, while brittle fracture is fast, and can take place at lower stress levels than a ductile fracture. Ductile fracture involves plastic deformation in the area of an advancing crack, and is a slow process. b) Fatigue: It is defined as
The construction methodology is the same with elastomeric bearings; however, the damping is increased by adding carbon block and other fillers. In addition, it has an adequate resistance to service loads. The damping characteristic is in between hysteric and viscous. The energy dissipation is linear and quadratic for hysteric and viscous, respectively. The energy absorption capability help reduced the earthquake energy transmitted to the superstructure.
When compared with stainless steel, carbon steels are readily rusted when reveal to the combination of moisture and air. Due to sufficient chromium presented in stainless steels endure passivation. Further this passive film protects steel surface by blocking diffusion of oxygen and thus protects the bulk metal from corrosion. So stainless steels are used both in corrosion resistance and where strength of steel is required. Stainless steels are roll into tube, wire, bars, plates and sheets where used in surgical instruments, cookware, and in construction material for large
The concrete should be used as efficient as possible. Nowadays researches efforts are continuously looking for new, better and efficient construction method. Various theories related to the analysis of structural elements reduced the self-weight of element for a given load- carrying capacity. Structural material optimization can reduce the dead load which reduce the contribution of seismic effect in high rise structures and also very good at the vibration dampers and heat isolation. According to the natural behaviour of the concrete, it is strong in compression and weak in tension.
The rate of cooling is immaterial except for some steels which are susceptible to temper brittleness. As the tempering is increased, the martensite of hardened steel passes through stages of tempered martensite and is gradually changed into a structure consisting of spheroids or cementite in a matrix of ferrite, formerly termed as sorbite. These changes are accompanied by a decreasing hardness and increasing toughness. The tempering temperature depends upon the desired properties and the purpose for which the steel is to be used. If considerable hardness is necessary then the tempering temperature needs to be low.
For example, vertical soil or rock surfaces. Glass : tempered glass is the choice recommended in high rise buildings as opposed to plain glass as it can resist various live loads and would not shatter. Some advantages and disadvantages of the type of materials used are: non corrosive, easy in casting (in situ) plasticity. Disadvantages can be, the cost to construct the dead weight, (weight associated with the structure) and the challenge or difficulty which may be encountered when pouring
The advantages of the Vickers hardness test are that extremely accurate readings can be taken, and just one type of indenter is used for all types of metals and surface treatments. Although thoroughly adaptable and very precise for testing the softest and hardest of materials, under varying loads, the Vickers machine is a floor standing unit that is rather more expensive than the Brinell or Rockwell machines. For aluminium alloys Rockwell B scale is used because aluminium is softer than
It has become an industry objective to reduce this distortion caused by heat treatments. Ideally, controlling the quenching process by changing the heat boundaries to minimize the distortion with the additional aim of satisfying residual stress and surface hardness distribution. (Heat treating) This experiment will be conducted on quenched, zinc coated steels. Knowledge of the phases of the carbon steels and knowing the properties of the different steels can be very beneficial in manipulating the heat treatment process to best suit what is desired. There are several impacts that should be noted about quenching a material.