Report 4 of 4: Back To The Future - India

Introduction

Since the early 1980s, the Indian State of Orissa has been collaborating with the British Government’s Department for International Development (DFID) to improve the general health of the population. One area in which this collaboration has been extremely active is the supply and maintenance of new health-care facilities.

The Andhra Pradesh Primary Education Programme – a joint initiative between the local government and DFID - has recently completed building a series of primary school classrooms utilising a wide variety of cost-effective construction technologies and innovative designs. Following the success of this initiative, the Government of Orissa entered into a partnership with DFID to develop and build a series of prototype Primary Health Centres, using locally available materials and labour, in three rural areas, Panasapada, Barikpur and Itamati, which required new or improved health-care facilities. The Government of Orissa supplied the funds and DFID provided the technical assistance.

The Project

The technical team given the responsibility of developing the demonstration project was primarily researching hospital designs, alternative building materials and delivery mechanisms in their quest to lower the initial cost of supplying adequate health-care facilities into the villages of Orissa. They also felt that the situation called for a consideration of all the environmental damage that is created around the supply of more traditional building materials, such as burnt brick and laterite stone blocks.

The project architect, after conducting the area-specific resource mapping exercise (existing health-care facility designs, local architectural concepts, availability of materials and construction skills etc.) worked with the Government’s Project Management Unit (all medical doctors) and a few selected district medical officers to develop three differing Primary Health Centre designs. These were to reflect local aspirations and also rationalise the actual small rural hospital requirements.

Three basic designs – circular, octagonal and a more traditional linear layout emerged out of this interactive process. Orissa lies along the cyclone prone Bay of Bengal so the circular and octagonal forms were chosen for their natural resistance to high winds. A variety of construction technologies and materials were used to construct the Primary Health Centres – under-reamed piles and stub foundation, rat-trap bonded brick and fly-ash block walling, filler slab, brick pyramid, hybrid, fly-ash vault and dome roofing.

The three projects have displayed an interesting variety of technologies and built forms:

• the Barikpur project takes inspiration from traditional Orissan Temple form with brick corbelled roofs;

• at Panasapada, blocks made from fly-ash generated from a local thermal power station were used both for walling as well as well for its vaulted roofs;

• the Itamati building has used fly-ash block masonry and clay tile filler roof slabs.

The durability and structural resilience of the applied technologies were amply demonstrated with all three buildings surviving the super cyclone of 1999.

Primary Health Centre at Barikpur

Barikpur is a small village in Bhadrak District of Orissa. The economy is agriculture based and generally poor. Barikpur is in a black cotton soil belt, which is the major reason for cracks in most of the buildings in the area. The reconnaissance helped in deciding the type of foundation. The local river, Baitarani, offers excellent soil for brick making and, as a result, there are many brick manufacturing units in Barikpur. Rat-trap bonded brick masonry walling was chosen, as it was cost-effective and environmentally less damaging than the other alternatives at that location.

Rat-trap bonded brick masonry

Rat-trap bonded brick masonry is used to build walls. The bricks are placed on their edges in 1:6 cement mortar and after the first layer of bricks has been laid, a gap is left between the bricks in the remaining courses (figure 1). This means that compared to a 230mm thick solid brick wall, the amount of bricks required to build the wall is reduced by 25 per cent and consequently, the amount of cement mortar needed is also reduced. The gap in the bricks helps to create thermal insulation, although it is not a good sound insulator. As the mortar is laid on each course, a wooden strip may be used to prevent mortar from falling into the cavities. With this technique, care must be taken to ensure that the wood is not left within the brick work.

Construction of the pyramids

The pyramids were constructed by corbelling or projecting each layer of bricks from the lower one. A curvilinear profile was introduced by regulating the projections of the corbelled brick courses, ranging from 62.5 millimetres to 87.5 millimetres. A parabolic profile is efficient in developing compression so a corbel of 62.5mm was used for the first five courses, followed by 75mm for the next eight courses and 87.5mm for the last thirteen courses.

The masons could construct two courses per day. The following day, they could stand on these (from the outside) and construct the next two courses; thus eliminating the necessity of shuttering.

Corbelled pyramids on square plan were used in the Primary Health Centre, whereas those in the staff quarters were on octagonal plans. The latter is more efficient structurally due to the reduced length of the base, which reduces the secondary bending moment.

The prototype Primary Health Centre and residential quarters for the doctor and the pharmacist were derived from the temples of Orissa. They were designed to demonstrate that upgrading traditional technology and craftsmanship, leads to a sustainable conservation of a dying art, as well as being cost-effective and socially appropriate.

Fly-ash as a building material

In India, the question of how to dispose of the power industry’s fly-ash build up has been debated for many years with the construction industry being a major contributor to this debate. For the past ten years, it has been common knowledge that fly-ash, when mixed with lime and gypsum, makes a strong durable building block, which has become commonly known as FAL-G.

The project constructed three demonstration Primary Health Centres, two of which have been built from FAL-G blocks. In the village of Panasapada, the walls were built from FAL-G and the roofs were constructed by using FAL-G blocks to build a continuous circular vault and several individual domes.

Across rural India, finding appropriate materials for forming shuttering which enables a large area of concrete roofing to be cast on is one of the major reasons for virtually all buildings being delayed. With this in mind, the technical team was keen to develop a roofing system that would minimise the use of shuttering. This resulted in a roof designed and constructed around a series of parabolic arches built with FAL-G blocks to form a continuous vault.

The Panasapada Primary Health Centre was designed and built as a circle around a central courtyard that is open to the sky. The room width between the interior and exterior walls is 3.2 metres.

Construction of the Primary Health Centre at Panasapada

The vault

A truss-type steel mould with parabolic arch profile was designed for a span of 3200mm. This had to be light enough to enable easy handling by two masons. Wheels were attached to each end of the mould to allow free movement after decentralising the individual arches.

The following steps were adopted for the construction of the FAL-G vault:

Step 1: Ring beam was cast along the top of the two external walls.

Step 2: The mould was placed on a 50mm thick wooden plank, which sat on a bed of wet sand. Levels at both ends of the mould were checked.

Step 3: FAL-G blocks were placed in 1:6 cement and sand mortar on the steel mould. Stone chips were hammered into the mortar joints to ensure contact between the adjacent blocks. A key block was cut to wedge shape and struck into the crown.

Step 4: The wet sand was removed from under the wooden planks with trowels until the mould came free.

Step 5: The mould was rolled to the next position and the process continued. On average, two masons and three helpers constructed eight arches per day. Because the main building was circular, it was not possible to bond the individual arches together. The primary arches were constructed with staggered FAL-G blocks for interlocking with the adjacent arches. The arches were constructed in a sequence that ensured equal loading around the diameter of the structure.

Step 6: On completion of all the individual arches, the gaps between them were later filled with blocks cut to corresponding wedge shapes. As a result, the individually built arches became laterally interconnected and stability of the vault increased considerably.

The main Primary Health Centre roof had 88 individual arches and required eleven working days to be completed.

The domes

The FAL-G domes of the two staff quarters were constructed on an octagonal platform. One continuous band lintel was cast around the walls at a height of 2100mm from the plinth level. Five courses of corbelled FAL-G masonry were laid on this band to gradually chamfer the corners thus converting the octagons into circles. A reinforced cement concrete ring beam was cast at this level to take the hoop tension exerted by the dome at the base. The domes were constructed in the same manner as the vault, but in this case, after the first arch was constructed, the mould was rotated by 90 degrees. The second arch was then constructed exactly as the previous one and so on.

The primary arches were constructed with staggered FAL-G blocks for interlocking with the adjacent arches. Radial placement of the arches created gaps which were later filled with blocks cut to wedge shape.

It is thought to be the first time that FAL-G material has been utilised to construct roofs. In the past, the public has shunned the use of fly ash based building products, the main reason being its grey drab colour. The exciting round design coupled with vaulted and domed roofs utilised in the Panasapada Primary Health Centre has shown that a drab coloured material does not mean that the end building need be dull.

Implementation of these technologies has developed the capacity of the engineers and artisans at village level. It is also worth mentioning that the roof worked out to be approximately 20% cheaper than a reinforced cement concrete slab of similar area. This has encouraged the Health Department of the Government of Orissa, to promote the use of FAL-G based technologies in all future projects.

The huge global demand for more and more physical infrastructure has resulted in an ever-increasing assault upon and consequently further degradation of the environment. The more commonly used construction materials, such as bricks, cement and steel, are produced through systems that are major contributors to this destructive cycle. At the same time, the manufacturing industries are producing millions of tons of potentially harmful waste. The PHC complex at Panasapada used approximately one thousand cubic metres of fly-ash which in its’ raw form is one of those potentially harmful wastes. This demonstrates that exciting modern structures can be built without constantly making use of materials such as bricks, cement and steel but by utilising materials and technologies derived from waste materials which with minimal processing can be both cost-effective and environmentally friendly.
 

For further information, please contact:
 

Sudpito Mukerjee DFID India B28 Tara Crescent Qutab Institute Area New Delhi – 010016 India Tel: +91 11 652 9123 Fax: +91 11 652 9296 E-mail: S-Mukerjee@dfid.gov.uk

For further technical information contact PK Das or Peu Bannerjee Das at: pkpeudas@del3.vsnl.net.in

ITDG would like to thank Sudipto Mukerjee, P. K. Das, Ms. Peu Banerjee Das and Roger Bonner for providing the original material on effective low cost building technologies in India.
 

This document is an output from a project funded by the UK Department for International Development (DFID) for the benefit of developing countries. The views expressed are not necessarily those of the DFID.

TVE/ Practical Action gratefully acknowledge support for the HANDS ON programmes from the UK's Department for International Development (DFID), the European Commission (EC), the UN Foundation and UNDP/The Equator Initiative in collaboration with the Government of Canada, IDRC, IUCN, BrasilConnects and the Nature Conservancy.