Essay On Structural Durability

EQUIPMENT USED • Moulds of cast iron or steel, with removable base plate were prepared. The depth of the mould and the distance between the two pairs of opposite internal side faces had nominal size of 150 ± 0.15mm. • A steel compacting bar weighing 1.8kg, 380mm long and having a ramming face 16mm diameter. • Sampling tray • Shovel Mixing The concrete was mixed by hand, the coarse aggregate were batched

This deposits the maximum dose below or on the skin surface. A bolus should be flexible and pliable so it can contour the skin surface without any air gaps. Paraffin wax, Vaseline gauze, wet gauze or towels, and water bags are noncommercial materials that can be used. Commercial materials have variable thicknesses or powder forms that can be mixed with water. Boluses may be applied on scars, superficial lymph nodes, or on uneven skin surfaces (McDermott & Orton, 2010).

Portland cement mixed with sand, gravel and water, a process called hydration, is how concrete is created. Crushed stone aggregate fine and coarse aggregates make up the bulk of a concrete mixture. Durability of concrete may be defined as the ability of concrete to resist weathering action, chemical attack, and abrasion while maintaining its desired engi-neering properties. Different concretes require different degrees of durability de-pending on the exposure environment and properties desired. For example, concrete exposed to tidal seawater will have different requirements than an indoor concrete floor.

Properties of Roller Compacted Concrete with Pozzolan as Cement Replacement Material Introduction: Roller compacted concrete (RCC) gets its name from the heavy vibratory steel drum and rubber-tired rollers used to compact it into its final form. RCC has similar strength properties and consists of the same basic ingredients as conventional concrete_ well graded aggregates, cementitious materials, and water_ but different mixture proportions. The largest difference between RCC mixtures and conventional concrete mixtures is that RCC has a higher percentage of fine aggregates, which allows for tight packing and consolidation [1]. RCC may be considered for applications where no-slump concrete can be transported, placed, and compacted

BiodentineTM has easy handling, excellent anatomic form, very good marginal adaption and establishes a very good inter-proximal contact, used as a permanent dentine substitute. Resin composite cannot be placed over biodentin as Grech et al advice postponing acid etching of biodentin 24 hrsupto 1 week alter setting in order not to effect the compressive strength of -biodentin(11,14).However, placing a Glass ionomer cement material over biodentin as a part of permanent or provisional should be considered . it has been claimed that conventional GIass ionomer can be layered over set biodentin after 12mins,which enables single visit procedures(15).Measuring the bond strength of conventional Glass ionomer to partially set has not been reported and might to support its usage in one-visit pulp therapy. Material and Method The material used in this study were BIODENTIN(SEPTODONT), and 2 conventional GICs, FUJI IX(GC, Tokyo,Japan) and Ketac Molar Easy mix (3M ESPE,St Paul ,MN).The compositions and powder –to –liquid ratio of the GIassinomer are listed in Table

Dental Stone with High Strength and Low Expansion (Type IV) After accomplishment of dehydration, another chemical such as 30% calcium chloride or magnesium chloride is added whilst boiling of gypsum product. The chlorides are later washed with hot water and since the solubilities of the hemihydrate and water are the same, it does not go into forming calcium sulfate dihydrate in presence of hot water. Furthermore, the powder that has been given out is the densest of all the gypsum types. Dental Stone with High Strength and High Expansion (Type V) The production of dental stone with high strength and high expansion is the same as type IV production. However they do differ in the way that type IV contains extra salts and therefore has reduced expansion during

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.

Concrete: cellular concrete of clay- gypsum and invention of light weight concrete Ferro concrete: this concrete is made up of a layer of fine mesh wire saturated with cement. Gunite: or commonly referred as a shot crete. This type or form of concrete is most commonly used in areas where formwork is limited or hard to use. Shoring up exposed vertical excavations, banks or surfaces susceptible to collapse. For example, vertical soil or rock surfaces.