Regional Seminar Papers 1997

The Right Tool for the Job, Review of Tools and Equipment for Labour-based Infrastructure Works: The Fit Programme Experience

Enoth Mbeine, Liaison Officer, FIT Uganda, MTAC, Nakawa, P. O. Box 24060, Kampala, Uganda. email: fituga@imul.com

Fit Programme

The FIT Programme is a technical assistance programme implemented through the ILO in Geneva. The FIT programme has been working in Kenya and Ghana for over three years to develop new and innovative approaches to the development and delivery of non financial business services to MSEs. From its work in Kenya and Ghana, FIT has developed a number of effective mechanisms for providing new and improved services and is now in the process of disseminating these to six other African countries.

FIT Uganda

FIT Uganda was established in February 1997 to introduce and adapt the FIT mechanisms to Uganda, and develop other new and innovative approaches to business services development.

User Led Innovation Methodology

User Led Innovation (ULI) activities were developed by the FIT Programme and have been successfully implemented in both Kenya and Ghana. ULI in essence, is a practical introduction of producers to the product development process. The activity involves a series of workshops and meetings which take the participants through a design process where new and improved products are suggested by the potential end users and customers.

Using the ULI approach, the end users can give the producers enough information to build innovative products. Ideally, they may also be the first customers for the prototypes, at the same time providing funds for further development as well as feedback on the performance of the new or improved products. The incorporation of local knowledge into the development of technological solutions, and the consequent ownership of the results, are two very important factors in favour of a participatory approach.

Methodology Sequence

Step 1- Identification of participants (a group of producers or their representatives and their existing and potential customers).

Step 2- One half day meeting between the producers or their representatives and one half day meeting between the users/customers to identify objectives and clarify the purpose of the activity. (orientation of participants)..

Step 3- One full day workshop bringing customers and end users together to identify the customers' needs for new and improved products and services. (brainstorming on new and improved products).

Step 4- Follow up workshops of participants to analyse the findings of the user/manufacturer (or representative) meeting, identify potential new and improved products and draw up an action plan (product identification).

Step 5- Small financial support provided to producers to prototype the identified new and improved products. Prototypes produced by manufacturers (product prototyping).

Step 6- Workshop for the manufacturers(or their representatives) to present their prototypes to the potential end users and customers. (product launch/testing).

User led innovation activity can be applied to a variety of sectors. This methodology applies to MSEs but this kind of experience could be very useful in the development of appropriate equipment for end users in Uganda. The equipment that cannot be manufactured locally in Uganda, should have some design recommendations by the end users. Here the representatives of the tool manufacturers should collaborate with road constructors who in turn should forward the appropriate designs for equipment in their respective areas.

Experience in Labour Intensive and Equipment Based Road and Canal Construction with Geocells

G J R van der Meulen and * A R M Hall, MABER General Consultants and Business Brokers, 3 Orchard Heights, Newlands 7700, South Africa; * Managing director, Manufacturers of HYSON-CELLS , P O Box 319 Muldersdrift 1747, South Africa

Summary

In the process of building the infrastructure, a premium is being paid for helping people bridge the development gap between agricultural existence and the industrial age. It is the task of the better educated members of society such as the technical and administrative personnel of local authorities to optimise the premium the population as a whole is paying via rates and taxes. Local manufacture of and expertise in the use of Geocells allows good, durable roads, ponds and canals to be built economically with a wide range of manual labour content to suit a wide range of conditions. A number of case histories are presented to demonstrate how the premium has at times been wasted and at other times has been fully utilised to enlarge the human capital of this country.

Introduction

Just as children cannot skip being teenagers before they become adults, all nations have to progress through stages of development.

After learning to make hand implements, mankind developed more sophisticated equipment to accomplish much work with little effort.

That is why it has become possible to build roads and canals economically and efficiently with capital-intensive equipment and a low labour content.

As the labour force has a tendency to strike, it is not surprising that some of the established contractors are not enthusiastic about and may even merely pay lip service to calls to involve local labour for community projects. This is particularly likely if the contractor is held responsible for the quality of the work and timely delivery and might face penalties over and above losses he might incur if the untrained and inexperienced labourers are uncooperative.

It has been accepted by the powers that be, that a premium cost over and above efficient economic industrial first world construction techniques is a small price to pay for peace and quiet when infrastructural projects have to be constructed in or for recently established communities.

The Aim of this Paper

Our aim is to show that through creative thinking, enthusiasm and utilising the energy and desire of people to improve themselves without losing sight of selfish and greedy behaviour, it has been possible to contain costs of infrastructural work so that more money is available for housing. As part of the construction project, the opportunity should be grasped to make it a valuable learning experience for members in the community, not only for learning new skills, but for appreciation that the quality of the work influences its useful life and therefore the benefit the whole community will derive from it.

Development

It was only recently that inhabitants in New Guinea emerged from the Stone Age because up till then those were the only implements they used in their mainly hunter-gatherer existence.

After man had become an agriculturist, he started to trade. As trade routes developed, money, its value system and uses and banking were developed.

With the coming of the industrial age, man was able to produce considerably more than he consumed.

In time, this excess wealth accumulated. We have inherited the wealth left by our predecessors and have added to that in our lifetime. This building we are in, the roads outside, the lights and electricity networks are but a few examples.

Most of the inhabitants of squatter camps have just left the agricultural stage of development and are expected to suddenly operate effectively in the industrial age, having completely skipped the lessons taught about the value system of money which is normally absorbed during the trading stage of development !

Therefore it behoves us to educate the people who are drawn into our projects, particularly labour intensive projects, to help them bridge the development gap and teach them the equation:

W = W (uku) S = (ubu) T

In English and Afrikaans - and in Xhosa

(work = wealth; werk = weelde) (ukusebenza = ubutyebi)

Most of us who have grown up in an industrial culture are used to "hiring and firing" and know that "output" and "productivity" are important factors in rating people and profit margins.

For us, "profit" is not a dirty word, because we know that there are four costs related to each product and that "profits" have to be "ploughed back" to provide the capital for survival and sustained growth. We also know that the less profit is set aside, the slower the development.

The four cost aspects are :

1. Cost of materials.
2. Cost of borrowing money to build the project.
3. Cost of salaries paid to the workers and the bosses.
4. Cost of the profit.

Unless people are taught that their perception that the profit is "merely an extra salary for the bosses" is incorrect, we cannot hope to improve productivity and efficiency

For a chosen profit and cost of borrowing money (related to a national bank), people should be shown that if a particular project is completed with the least amount of waste of materials, it will leave more for salaries for both the workers and the bosses. Hence, there is an incentive for them to work together and maximise the benefits from the project.

We, in this room, understand the law of economics, known as the "law of supply and demand", or rather we think we do. We believe that if something is in short supply, its value is high and if it is abundant, its value is low. Because all raw materials are finite in quantity and the labour force is infinitely renewable, all materials should be expensive and labour cheap when viewed in global terms.

However, from an individual's point of view one's life and therefore the hours of labour which can be sold is limited in comparison with the materials which are consumed in a life time and hence we rate labour expensive and do not mind wasting materials.

In the regions where there is the greatest need for infrastructure, we find the greatest concentration of people who have just left the agricultural age. A few spaza and taxi owners have entered the trading stage of development, even fewer industrial age.

Part of the reason for the problems which have arisen and are arising in labour intensive projects is that the participants have not taken cognisance of these factors.

What is Success?

Success is achieved when set objectives have been reached.

As town engineers, town clerks, designers and contractors, we are merely the administrators for the politicians who are our bosses and the tax/rate payers who are the financiers.

Is our objective to have a project built and provide employment to some nameless people to pander to promises made by politicians?

Or should our objective be wider? Should we do the above and at the same time help a few people to utilise this opportunity to bridge the development gap and hopefully in the process discover and grow some entrepreneurial material? Entrepreneurs in small firms are known to be the best creators of jobs. Should our objective also be to minimise waste of materials and the cost of borrowing money (penalties for late completion are a kind of measure of the cost of money) and thus allow us to spread the taxpayer's money farther and make the remainder available for housing?

Should our objective also include delivery of a good, sound, sustainable quality product which will minimise future maintenance costs because the community has developed a sense of ownership and therefore will tend to protect their inheritance of the wealth of others from vandalism and abuse?

Geocells and Paving

Geocells can have hexagonal cells like a honeycomb or more or less square cells. The heights of the mats generally range from 50 to 200mm but some of them can be manufactured up to 4000mm high.

A Geocell manufactured in this country has become so successful that it has given rise to competing products.

Geocells are not only used for building soil filled weirs, dams, earth retaining walls and vegetated bank protection but also, when they are filled with concrete, for building canal linings, spillways, pond linings, roads and container yards.

The walls of the cells can be porous or impermeable and can range in thickness from 50 micron to 4mm.

When the walls are porous and thin, the danger exists that the cement grout bonds the adjacent blocks and the final product behaves like a solid mass concrete slab.

When the walls comprise high density polyethylene or PVC, they act as a permanent formwork for individual blocks with minute evenly spaced joints caused by the shrinkage of concrete.

If the thickness of the polyethylene is less than 500 micron, the cell walls can deform enough to give sufficient three-dimensional interlock so that individual blocks cannot be punched through the paving nor be sucked out of canal linings.

Geocells generally do not have strings threaded through them. One locally manufactured Geocell with threaded polypropylene strings has withstood a patent infringement in America. The strings assist in holding up the walls of the mat when the cells are being filled and they are used to pull the mat onto the support media and so prevent a sheet of waste concrete under the cells. They help to create corrugations which improve the interlock and help to anchor mats to steep stable slopes.

When a three dimensional interlock between adjacent blocks is achieved, a paving resists point loads like chain-mail armour resisted spears and arrows in combat. Because the individual interlocking blocks can be made robust, it is not necessary to use reinforcing steel in paving and therefore aggregates contaminated with salt and calcium chloride based accelerators can be used with impunity.

Stretching of the Geocells mat and securing it to the support stratum prior to filling is done by hand. The preparatory and the subsequent work can be done either mechanically or manually. Consequently, a wide range of manual labour content can be accommodated in projects where Geocells are utilised.

For convenience, one supplier refers to four categories or working conditions as indicated in Table 1 for concrete paving.

Concrete/Grouted Stone Mixes and Strengths

Concrete comprises aggregates, cement, water and air.

Table 1: Working conditions

Conventionally all these components are premixed at once before being placed in moulds but there should be no objection to changing the mixing and/or placing sequence as long as the end product is concrete.

It has been found that as soon as the cells are filled with soil or stone, the surface can be trafficked and therefore filling the cells with stone first and then with a sand, cement and water grout afterwards is a very practical way of achieving a concrete paving with unskilled people.

To minimise the air content (i.e. prevent honeycombing), the grout must be fluid, the stone clean and large and tamping or vibration is required to bring the air out.

The method is flexible because the grouting can be stopped at any convenient time and cell boundary and breakdown of the mixer does not stop the progress of other operations.

As people become more skilled and contractors wish to increase their production rates, a natural progression from Third or Second World conditions towards First World conditions tends to develop.

Concrete with 30 to 50mm slump which is suitable for normal concrete work, particularly where poker vibrators are used, is not suitable for use with Geocells. It compresses or collapses the cell walls (there is no easy way to establish this), reduces the resulting thickness of the paving and is difficult to spread.

Therefore concrete with a slump of in the order of 150mm must be used. (On steep slopes a slightly lower workability is more appropriate). Such concrete, however, usually segregates severely during transport in a wheelbarrow and separates into slush and a very stiff concrete. The latter collapses the cells when tipped. This can be overcome with air entrainers and other suitable additives as is done by the ready mix plants who now have "Hyson mixes" in their computers.

For Third World conditions the use of sophisticated additives is not appropriate and "wheelbarrow concrete" has to be used.

Because the sources of the aggregates vary widely, concretes with identical mix proportions and workability will exhibit different strengths. Where the strength of the concrete in say stormwater canals may not be critical, it may be easier and more appropriate to specify mix proportions as that is easily checked.

However, where strength is of importance such as in loaded road pavings, it is easier to specify a strength criterion. The appropriate mix proportions will then have to be established and checked by means of cores.

Mrs A.R.M. Hall was made "Concrete Woman of the Year" in 1995 by the Concrete Cement Institute for her contributions in this field of unconventional concrete work. It was found that for the kind of mixes used in grouted stone work the approximate strengths shown in Table 2 can generally be anticipated.

Table 2: Grouted stone mixes

It would appear that the initial interlock of the stone prior to grouting has a noticeable effect upon the compressive strength because if the same ingredients are premixed and placed in a cube mould, the compressive strength is less. Therefore coring is the best way of controlling the quality. A reasonable approximation can be obtained by prepacking stone in a cube mould and then tilting the mould on a corner while the grout is poured in so that no air is trapped as the mould is gradually placed horizontally during the grout being filled to the top. Placing the mould on a vibrating table disturbs the stone and changes the strength !

A slump cone is a recognised First World piece of equipment to control the workability of concrete. For Second and Third World conditions two litre plastic cool drink bottles which are readily obtainable can be used instead. When the bottom of such a bottle has been cut off and the bottle filled with concrete, the slump which results when the bottle is inverted, the top unscrewed and the bottle lifted, approximates the real slump done with a slump cone when the workability is about 150mm.

The same bottle can be used to assess the correct fluidity/flowability of the grout. The correct fluidity depends upon the absorption of the stone, its cleanliness and size as well as the depth of the cells. The fluidity should be such that two litres of grout should empty out of the neck of the bottle in 6 to 10 seconds to ensure full penetration of the stone bed.

Assistance from the supervising engineer/technician is required to establish the amount of water required for each of the "wheelbarrow concrete mixes" which straddle the strength which has been specified to give a 150mm "bottle slump". Table 3 shows the approximate strengths which can be expected for the various mixes. This first mix is mixed conventionally on an impervious surface with the dry components being mixed first and the water being added until the desired slump has been achieved.

Table 3: Approximate strengths of wheelbarrow mixes

Because wheelbarrows have a 30 litre capacity and segregation takes place during transport, the following procedure must be followed when concrete for use in Geocells is mixed on site:

Five litre plastic flower pots which have a hole in the bottom are used to measure the volumes of the materials because buckets are stolen.

Firstly, the cement and the previously established measured volume of water (plastic bottle containers) are mixed. 10 litres of stone is then added and mixed. The mixture is then wheeled to the casting area

At the casting area, 10 litres of sand is sieved into the mix while it is being turned over. (Like sieving flour into a cake mix to prevent lumps, the sand has to be sieved into the mix to ensure homogeneity). When the mixing is completed, the concrete is immediately poured into the cells.

Case Histories

A number of projects have been selected and will be described briefly to show to what extent the wider objective discussed earlier may or may not have been met.

Some of the projects may act as an inspiration for others to simulate or build onto. Much of what has been learned is thanks to the enthusiasm and involvement of the people who were committed and were willing to move into uncharted waters.

Case History No. 1

Project Name: Vosloorus Minor Stormwater Canal

Scope: 1,600m² - Ready mixed concrete in 200mm x 200mm x 100mm Geocells

Contractor: Protech Construction (Pty) Ltd

Contract Manager: Gerrit van Schalkwyk

Geocells Trainer: Paul Molapo

Consulting Engineer: Bradford Conning & Partners

The contract had specified that the contractor had to employ local labour. The local political party and the community structures had insisted that payment had to be on an hourly basis and this was incorporated in the documents.

When the project started, someone advised the local labour to work slowly and spin out the contract so that they would earn more. As this would have caused a loss to the contractor, he threatened to abandon the contract.

The trainer which the Geocells manufacturer supplied on that project, Paul Molapo, then acted as mediator and explained to the labourers and community members that unless a reasonable production rate was achieved, the contract would fail and they would earn nothing further.

This resolved a major crisis but the ultimate result was still a poorly constructed and finished canal with barely sufficient concrete on the one side where it had to be thrown by hand and too much on the other side where the ready mixed concrete truck had good access and the concrete was placed directly into the cells from the truck. However, if there was excess concrete it was merely spread and not worked forward as the work progressed.

Consequently, in my estimation, at least 10% to 15% more concrete was used than was required. The ready mixed plant was probably the main beneficiary.

This project probably only met the narrow objective and has left both the contractor and the consultant with negative feelings.

Case History No. 2

Project Name: Mfuleni Bulk Stormwater Upgrade

Scope: 17,000m³ grouted stone - 150mm x 150mm x 100mm Geocells

Contractor: Ken Stephens Construction (Pty) Ltd

Consulting Engineer: Gibb Africa

A minimum number of mandays of local labour had to be used by the contractor. The labour was paid on an hourly basis. They comprised the major portion of the labour force and three strikes occurred mainly for additional fringe benefits.

Initially, concrete mixers were used to mix the grout. Wheelbarrows and the front end loader bucket were used to carry the grout to the canal, but the productivity was low.

When the minimum requirement for the use of the labour had been met, the contractor had to reduce the labour force (not without pain) and employ ready mixed grout to increase the production rate in order to meet his completion date.

The contractor has accepted that "this is the way things are these days" and the narrow objective has been met. Hopefully, some of the retrenched workers may have noticed that too much striking and low productivity lost them the wages they could have earned and which were ultimately paid to the ready mixed plant and its workers from "outside". It is doubtful however if this lesson was learnt, unless someone pointed that out to them.

Case History No. 3

Project: Irrigation Drainage Canal - Upington

Scope: 7.4 km long, 7.5 m wide grouted stone - 200mm x 200mm x 75mm Geocells

Authority: Department of Water Affairs

Reference: Mr G Meiring

The construction of a much needed, overgrown and choked drainage canal in the irrigation system had been delayed. There was a clash between the use of the canal by farmers and the access required by the Department to construct a conventional trapezoidal reinforced concrete canal.

The canal was built under Third World conditions by a team of 12 permanent employees supplemented by five to six labourers seconded by each successive farmer along the canal.

It has been estimated that the project cost the Department about R150 000 less than conventional construction.

Although the casual farm workers were probably not assisted in bridging the development gap, the project was partly successful in the broader objective because tax payer's funds were saved in comparison with the conventional approach.

Case History No. 4

Irrigation Canal: Pongola

Scope: 1.2 km with 10m perimeter and 2m deep 20 MPa ready mixed

concrete 150mm x 150mm x 100mm Geocells

Authority: Department of Water Affairs

Reference: Mr B Bosman

Through a misunderstanding ,the use of a particular type of Geocells had been banned in the department until Mrs Hall had discussions with Minister Kader Asmal. It was then decided to install a trial section in one of the new canals being constructed.

The results were sufficiently promising despite the initial low production rates at the start of the learning curve, that it was decided to build another portion of the work.

The normal production rate to build this conventional trapezoidal canal with doubly reinforced concrete panels and rubber expansion joints averaged about 350m²/day with First World equipment and a trained labour team of 60.

With concreted Geocells peak production rates of 1,100m²/day were reached with a team of 18 when the consistency of the ready mixed concrete, which could be delivered on both sides of the canal, had been optimised. The cost of the finished canal lining was about one-third that of the conventional construction.

This indicates the potential economies of scale obtainable with First World production and therefore indicates the kind of premiums we are paying for helping people over the development gap.

Case History No. 5

Project Name: Vosloorus Ext 14 - Stormwater Canal

Scope: ± 10,000m² to date - ready mixed concrete - 200mm x 200mm x 100mm Geocells

Contractor: Emergent Contractors

Consulting Engineer: Stewart Scott

Reference: Mr R Stone

The project was divided into sections with the intention of not only building the canal but also of creating new contractors.

The raw labour force was trained in the use of Geocells and concrete and the concept of task based remuneration. As this was initially not understood, there were some stoppages and problems at the start. Also it was difficult to instil pride and overcome an attitude of "if it is not right, that is just tough".

At the start, laying rates in the order of 70m²/day were achievable when the earthworks were ready.

When the first section had been completed, the 15 embryo emerging contractor groups which had been trained up consolidated into four firms which tendered on the basis of their own estimated production rates. The firms are paid and retention is withheld in the conventional manner. The production rates are now about double the initial rates. Not only is the canal being completed, but the wider objective of bridging the development gap is taking place.

Case History No. 6

Project Name: Kwamashu Road

Scope: 6,000m² grouted stone 200mm x 200mm x 100mm Geocells 2,000m² grouted stone 200mm x 200mm x 75mm Geocells

Contractor: W K Construction

Reference: Mr A Flemming

The roads were constructed on G5 and G6 material and finished with a broom finish.

The stone was 37.5mm size and the grout was three buckets of sand to three buckets of cement with ± 30 litres of water. Initially the grout was mixed in a concrete mixer and production was low.

Hippo roller mixers were then tried. A team of men measured the material into the roller mixers and women pulled them to the working face at roughly the same production rate as before but this improved later. The mixers worked well except that the holes where the handles fitted had to be modified.

At the negotiations with the community, it was agreed to pay on a task rate per day related to a production rate of 100m²/day, i.e. effectively at a rate per square meter produced.

Initially, the production rates were low but improved with time, because there was a willingness to try an entirely new approach.

A serious problem existed with theft of cement.

This indicates that the project merely achieved the narrow objective as there clearly still existed a "steal from them for us" attitude and no incentive or flexibility existed to reduce costs for the taxpayer nor to increase benefits for the recipient community as a whole.

Case History No. 7

Project: Township roads in Eluxoliweni

Scope: 3,000m² grouted stone 150mm x 150mm x 75mm Geocells

Authority: Municipality of East London

Reference: Mr S Schroeder

The need had been established to surface steep gravel township roads which washed away in the rain.

It was decided to try grouted stone Geocells construction, although its initial cost was estimated to be higher than a single seal bitumen spray, because the latter was not expected to give long term service.

The then roads design technician, Mr Schroeder, was involved in the initial negotiations with the community and the execution of the work.

He had initial problems during the setting out of the works when one of his labourers was attacked and also later when the Sotho trainer, Joseph Nyembe, who was sent by the Geocells manufacturer to train the construction team, was attacked.

Mr Schroeder took the matter up with the then community leader (who is now the deputy mayor of the town) and told him to sort out his community or otherwise the roads would not be built.

This caused quite a furore but resulted in support from the community.

In addition to the equipment, municipal overalls were supplied to the workers, which helped to give them status. The grout was supplied from a ready mixed truck.

In the beginning, the informal leader of the group of workers was assertive and caused trouble. However, he served as the communication channel through a message was transmitted that enough money was available to build two roads from which they would earn a part. However, if they worked harder, they would still earn and they might be able to build further and the community as a whole would reap the benefits. In the event three roads were built from the budgeted funds.

When there was a problem with the finish of the work, Mr Schroeder asked them, whose road it was - his or theirs? This caused some embarrassment and the quality of the work immediately improved again.

The obstreperous leader was afterwards recommended for work in a sweet factory and is reported to be a star.

This project clearly can be rated as a highly successful project because it has achieved practically all the objectives enumerated above and demonstrates the importance of personal commitment of all the participants, which included the leaders in both the then council and the community.

Conclusion

Because the labour content is a high proportion of the cost of infrastructural work and its quality effects the service life of the facility, it is important to create the right attitude in the labour force and a sense of ownership in the recipient community.

Case history no. 4 demonstrates that the most efficient manner of building the infrastructure in this country is by means of large scale First World techniques.

However, with that process, we will not address the development gap, which has to be done to create peace and prosperity and therefore we have to accept that a premium must be paid for education while we build the infrastructure a little slower. This education is a painful process, particularly for the students

As teachers we have the choice of how to spend the premiums in one of two ways. One way is to spend it at the start of a project and invest it in good communication and offer a bonus to the community as a whole by providing more for the same money in the end.

Alternatively, we can allow matters to take their course and the premium will be spent on waste, theft, work stoppages, financial losses and interest to financiers and although the few employed labourers may have gained individually some more money for uninspiring work in the short term, they will not have developed pride and long term knowledge and skills.

The responsibility of that choice is ours as the administrators for society.