The bricks utilized in construction area unit classified as:
(i) First class bricks
(ii) Second class bricks
(iii) Third class bricks
(iv) Fourth class bricks
(i) First class Bricks:
These bricks area unit of normal form and size. They’re burnt in kilns. They fulfill all fascinating properties of bricks.
(ii) Second class Bricks:
These bricks area unit ground shaped and burnt in kilns. The sides might not be sharp and uniform. The surface is also somewhat rough. Such bricks area unit unremarkably used for the development of walls that area unit planning to be plastered.
(iii) Third class Bricks:
These bricks area unit ground shaped and burnt in clamps. Their edges area unit somewhat distorted. They turn out uninteresting sound once affected along. They’re used for temporary and unimportant structures.
(iv) Fourth class Bricks:
These area unit the over burnt bricks. They’re dark in color. The form is irregular. They’re used as aggregates for concrete in foundations, floors and roads.
Uses of Bricks Bricks area unit utilized in the subsequent civil works:
(i) As building blocks.
(ii) For lining of ovens, furnaces and chimneys.
(iii) For protective steel columns from hearth.
(iv) As aggregates in providing water proofing to R.C.C. roofs.
(v) For pavers for footpaths and cycle tracks.
(vi) For lining sewer lines.
It is a crucial binding material utilized in building construction. Lime has been used because the material of construction from ancient time. Once it’s mixed with sand it provides lime mortar and once mixed with sand and coarse mixture, it forms lime concrete.
Types of Limes and their Properties
The limes area unit classified as fat lime, hydraulic lime and poor lime:
(i) Fat lime:
It is composed of ninety five proportion of oxide. Once water is supplementary, it slakes smartly and its volume will increase to a pair of to 2( 1/ 2) times. It’s white in color. Its properties are:
(a) Hardens slowly
(b) Has high degree of malleability
(c) Sets slowly within the presence of air
(d) White in color
(e) Slakes smartly.
(ii) Hydraulic lime:
It contains clay and metal compound. Relying upon the proportion of clay gift, the hydraulic lime is split into the subsequent 3 types:
(a) Feebly hydraulic lime (5 to 100% clay content)
(b) Moderately hydraulic lime (11 to twenty clay content)
(c) Eminently hydraulic lime (21 to half-hour clay content) the properties of hydraulic limes are:
• Sets below water
• Color isn’t dead white
• Forms a skinny paste with water and don’t dissolve in water.
• Its binding property improves if its fine powder is mixed with sand and unbroken within the kind of heap for every week, before victimization.
iii) Poor lime:
It contains quite half-hour clay. Its color is muddy. It’s poor binding property. The mortar created with such lime is employed for inferior works. IS 712-1973 categories lime as class A, B, C, D and E. category A Lime: it’s preponderantly hydraulic lime. It ordinarily provided as lime hydrate and is usually used for structural works.
Category B Lime: It contains each hydraulic lime and fat lime. It’s provided as lime hydrate or as fast lime. It’s used for creating mortar for masonry works.
Category C Lime: it’s preponderantly fat lime, provided each as fast lime and fat limit is out there in standard and block kind. It’s provided as lime hydrate. It’s unremarkable used for masonry mortar.
Tests on Limestones
The following sensible tests area unit created on limestones to work out their suitability:
(i) Physical tests
(ii) Heat take a look at
(iii) Chemical take a look at
(iv) Ball take a look at.
(i) Physical Test:
Pure rock is white in color. Hydraulic limestones area unit dark-blue gray, brown or area unit having dark colors. The hydraulic lime provides out earthy smell. They’re having clayey style. The presence of lumps provide indication of fast lime and unburnt lime stones.
(ii) Heat Test:
A piece of dry stone deliberation W1 is heated in associate degree shoot for few hours. If weight of sample once cooling is W2, the loss of weight is W2 – W1. The loss of weight indicates the quantity of greenhouse gas. From this the quantity of carbonate in rock is figured out.
(iii) Chemical Test:
A teaspoon jam-packed with lime is placed during a tube and dilute acid is poured in it. The content is stirred and also the tube is unbroken within the indicate twenty four hours. Vigorous effervescence and fewer residue indicates pure rock. If effervescence is a smaller amount and residue is additional it indicates impure rock.
If thick gel is created and once tube is command the other way up it’s potential to spot category of lime as indicated below:
• Category A lime, if gel don’t flow.
• Category B lime, if gel tends to flow down.
• Category C lime, if there’s no gel formation.
iv) Ball Test:
This take a look at is conducted to spot whether or not the lime belongs to category C or to category B. By adding adequate water regarding forty millimeter size lime balls area unit created and that they area unit left undisturbed for 6 hours. Then the balls area unit placed during a basin of water. If at intervals minute’s slow enlargement and slow disintegration starts it indicates category C lime.
Uses of Lime
The following area unit the uses of lime in civil works:
(i) For white laundry.
(ii) For creating mortar for masonry works and daubing.
(iii) To turn out lime sand bricks.
(iv) For soil stabilization.
(v) As a refractory material for lining open fireplace furnaces.
(vi) For creating cement.