MATERIALS & CONSTRUCTION TECHNOLOGY MATERIALS & CONSTRUCTION TECHNOLOGY PALESTINE UNIVERSITY Second semester Dr. Ali I. Tayeh

PALESTINE UNIVERSITY Chapter No. 3 Lime

Lime General Lime is a very important building material. It has been in use since ancient times. Egyptians used to use lime for plastering works and Romans for plastering, mortar, and concrete works. In India, there are numerous historical constructions, where lime had been used in the form of cementing, material. Even to- day, lime is a very important material not only for building purposes, but also in so many other manufacturing processes.

1. It has good plastic properties. 2. It gives strength to the masonry, when used as mortar. 3. It stiffens quite easily and in short time. 4. It is easily workable. 5. It has good adhering properties with stone and bricks both. 6. Its shrinkage is comparatively low.  Properties of Lime

 Uses of Lime The lime can be used for following purposes. 1. As a binding material in mortar. 2. As a binding material in concretes. 3. As an aggregate in form of crushed lime stone. 4. For plastering. 5. It is used for preparing lime-sand bricks. 6. It is used as a fluxing material in many manufacturing processes. 7. It may be used for masonry work in form of lime stone. 8. It used for improving soils for agriculture purposes. 9.It used in paints. 10.It used for the manufacture of glass. 11.It is used for water purification and sewage treatment works.

 Source of Lime

 Varieties of lime Depending upon the sources 1. Stone lime. It is almost pure lime. 2. Kankar lime. It is impure lime. 3. Shell limc. II is purest form of lime.  Classification of Lime I. Fat lime. 2. Hydraulic lime. 3. Poor lime.

This lime is known as fat lime, because it increases 2 to 2.5 times in volume, when slaked. This lime is obtained by burning comparatively pure lime stone. This lime is also sometimes known as pure lime, rich lime, white lime or high calcium lime. The lime stone from which this lime is obtained should contain about 95% calcium oxide and about 5% other materials.  Fat lime

 The properties of fat lime 1. Its hardening action is slow. 2. Its setting action is also slow. 3. It swells 2 to 2.5 times of quick lime after slaking. 4. It has a very high degree of plasticity. 5. It is soluble in water.. 6. It is milky white in its purest form.  uses of fat lime (i) For white washing (ii) For plastering (iii) Its mortar with sand may be used for thin masonry works.

 Hydraulic lime This lime has the property of setting under water. It is obtained by burning lime stone, containing a lot of clay (Silica and Alumina). (Silica and Alumina). These limes may be further divided into following three categories. 1. Feebly Hydraulic lime. It contains silica, alumina and/or iron oxide less than 15%. The usual percentage of these constituents varies between 5% to 10%. On slacking, it increases in volume by very small amount. It slakes slowly. This lime may be used in forms of mortar with sand in not very important works.

2. Moderately Hydraulic lime. This lime contains 15 to 25% silica and alumina. It slakes very slowly and increases by very small amount on slaking. It is mostly used as mortar in good type of masonry works. 3. Eminently hydraulic lime. This lime is better quality than moderately hydraulic lime. It contains 25 to 30% clay (silica and alumina). Its initial setting starts after 2 hours and the final setting 48 hours. This lime is mostly used for structural purposes and for the works carried out under water or in damp situations.

Properties of hydraulic lime can be summarized as follows: 1. This lime is not perfectly white. 2. It can set under situations where free air can not reach. (lime does not depend upon atmospheric air). (lime does not depend upon atmospheric air). 3. It can set under water. This lime contains more than 30% of clay. It slakes very slowly. It does not dissolve in water. This lime is also known-as lean lime or impure lime. lime hardens and sets very slowly. This lime used for inferior works only.  Properties of hydraulic lime  Poor Lime

L Hydraulic lime mortar-lime: sand: : I : Adhesive strength (with bricks) after 7 days curing = 2.25 kg/cm2. 3.Tensile strength (1 sq. inch) after 21 days of curing = 6.3 Kg/cm2. 4. Compressive strength (5 to 7.5 cm cube test ) after 21 days of curing = 35 Kg/cm2 4. Compressive strength (5 to 7.5 cm cube test ) after 21 days of curing = 35 Kg/cm2.  Testing of Lime

End Lime