[Homestead] Alker mixes, Dr. Bilge Isik

Tvoivozhd tvoivozd at infionline.net
Tue Sep 14 23:41:03 EDT 2004

Dr. Bilge Isik is like a will o' the wisp---easy to find in 1997, and a 
lot more data than here. I found him again several years ago, but his 
website disappeared again.


February 14, 1997
Southern California Institute of Architecture
Assoc. Professor
Istanbul Technical University
Istanbul - TURKIYE



    * *Purpose*
    * *The Soil*
    * *Proportionning of Gypsum + Lime Adobe (ALKER)*
    * *Properties of ALKER*
    * *Workability*
    * *Curing*
    * *Construction*
    * *Labor*

*Earthen construction is vulnerable to moisture and can be easily 
damaged by earthquake. However, indoor quality in earthen construction 
is very healthy. It provides protection against hot and cold weather 
conditions, in view of its high thermal capacity and insulating values. 
Because of these advantages, earthen construction technology is subject 
to research in both in the industrialized and unindustrialized countries.

In this research, gypsum and lime are mixed to the soil to promote the 
properties of the material. The gypsum stabilized soil sets in a short 
time, which makes the production time shorter and the curing 
unnecessary. It also makes the production period independent from the 
rainy days. The material is porous, thereby increases the insulting value.

The mechanized construction technology for the gypsum stabilized earthen 
construction aims to improve the local construction material for 
mass-housing. It will also contribute to preserve the natural sources 
and save funds for the country.

*The Soil
To obtain required strength and durability*
*Traditional Earthen Construction * 	*ALKER construction*
preprocessing 	preprocessing is not necessary


setting the soil aside 	

30% clay 	10% clay

*Proportion of ALKER*(Gypsum + Lime Adobe)


*Ingredient * 	*% by Weight * 	*Practical Measures *
*Soil* 	100 	2 full wheel barrow
*Gypsum* 	10 	4 shovel full
*Lime* 	2 	1 shovel full
*Water* 	18-20 	1 bucket full

*General Properties*


    * improves the water absorption property
    * improves the mechanical properties
    * improvers the heat insulation
    * low shrinkage
    * clean surface
    * short setting
    * short construction time

*Physical Properties*

Unit weight 	1.6-1.7 kg/lt
Shrinkage 	1.0-1.5%
Compressive strength 	2.0-4.0 N/mm2
Shear strength 	0.9-1.3 N/mm2
Water absorbtion 	very low
Long term water exposure
(except direct rainfall) 	no erosion
Heat transfer value l 	0.4-0.5 kcal/mhC
Specific calorific 	1.0 kJ/kgK



*Water Content * 	*Workability*
18-29% 	rammed earth
20-22% 	adobe blocks
24% and more 	segregation

*To obtain required strength and durability
*Traditional earth *
*construction * 	*ALKER construction*
15-21 days strengthing 	20 min. strengthing
curing area 	no curing area
water sprinkling 	no water sprinkling
rain protection 	no rain protection



    * The gypsum stabilization enables a shorter construction time
    * The external walls are 45cm tick, this provides thermal property
    * The load bearing internal walls are 30cm
    * Wall oppennings are 25%
    * Foundations and tie beams are reinforced concrete

ALKER technique decreases a number of processes*

    * 4 laborers can erect 2.5-4.5 m3 of walls/day
    * 100 m2 house has approximately 45 m3 walls, therefor, 4 laborers
      can complete a hose in 10 days

*Production Method of Gypsum Adobe (ALKER)
_Material :_*

*Earth:___________*100 kg__________100%
without humus
clay (appr. %10) + silt + sand + grvel (7 cm)
*Water:*____________20 kg__________20%
*Gypsum:*___________10 kg__________10%
*Lime:*______________2 kg___________2%

*_Mixing :_* mechanical mixer (or shovel)

*_Process :_*
mixer + earth + 2 kg water 	2 minutes mechanical mixing
barrow + water 18 kg + lime 2 kg + gypsum 10 kg 	2 minutes hand mixing
pour the barrow full of mixture into the mixer
(water 18 kg + lime 2 kg + gypsum 10 kg) 	3 minutes mixing
pour the mixture to the wheel borrow; ramm it into the wall form 	in no 
longer than 15 minutes

Please inform Bilge ISIK <mailto:isikb at itu.edu.tr>about the results with 
your full address and a short CV.
Your interest is appreciated.

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