via ZRA backtracks on Kariba collapse fears 22/03/2014 NewZimbabwe
THE Zambezi River Authority (ZRA) on Thursday backtracked on claims early in the week suggesting Kariba Dam wall was facing collapse which would threaten some 3.5 million people in the sub-region.
ZRA officials were quoted saying some $250 million was needed to carry out urgent repairs on the hydroelectric dam bordering Zambia and Zimbabwe.
Kariba is one of the world’s largest dams, measuring 128 metres tall and 579 metres long.
In a short statement, the joint Zambia and Zimbabwe Kariba dam regulatory body said: “We would like to inform the public that comments in the media which said Kariba Dam wall faces collapse were made during a roundtable discussion with co-operating partners.
“Scenarios were presented on what could happen should rehabilitation works not be taken up with urgency. Please, DO NOT BE ALARMED.
“Measures are underway to start the rehabilitation process in the third quarter of the year. The meeting at which these issues were presented was to raise funds for the works to start around September.”
NewZimbabwe.com last year visited Kariba Dam on as part of a media fact-finding mission during the dam’s March annual gate openings and witnessed cracks that had developed on the dam wall.
Engineers, at the time, ruled out any possible dam wall collapsing although it was clear the cracks were growing.
Over one million cubic metres of concrete was poured into the 36.6 metre high wall with a thickness of over twenty four metres to sustain the pressure of nearly ten million litres of water passing through the spillway each second.
COMMENTS
What do we believe now?If cracks are there it means the wall is beginning to weaken so its better to repair it now otherwise these cracks will increase in size.
The cracks in the concrete are most likely caused not by any fundamental weakness in the concrete – after all it has lasted intact for 50 years. Every dam is a combination of the man made structures and the natural rock and soil on which the dam has been built. Kariba dam wall has been keyed into a notoriously unstable south bank, which tends to slide downstream. Engineers in ZRA have been monitoring this for years.
The cracks in the Kariba dam wall are most likely caused in part by stress redistribution as the foundation at the base of the dam wall gets eroded away. The load that was previously carried by the footing is now being transferred to and carried by the rigid concrete wall, causing it to crack, and to weaken.
An 81 meter (eighty one meters – the height of Karigamombe building !!!) deep hole in the bedrock immediately downstream of the dam wall is very severe and is certainly likely to push the entire structure closer to failure. It should not have been allowed to get so deep. Lets hope that in the coming dry season the relevant authorities (ZRA / Govts of Zambia and Zimbabwe??) are able to mix enough of Apolitical’s perfect concrete to pour and fix into that deep hole so that it can bear part of the load and stabilize the dam footing.
I completely agree that this is time for the very best engineers to be flown in to guide the repair work.
Otherwise it will be a very long dark night for us all.
Crack are caused in concreted when the mixing of aggregate is substandard – that is an engineering fact.
But the standard of consultancy is frightening as repairing the problem if not as simple as cracks in a wall in your home – you cant get away with filler.
When there are cracks there is also movement and that is the priority yet to be discussed.
Movement is due to the friable rock side wall – where frankly a dam should never have been built.
Also the siltation which amounts to hundreds of tons against the wall. To give an indication tom lawmen of the degree of siltation in the Zambezi the area that floods in Mozambique from tete to the sea is estimated to have silted up by 500 million tons – hence the flooding.
They have knowledge of how to desilt it so they look at the erosion because they know that a hose pipe digs a hole in a garden and that the gullible will believe it.
With the standard of consultation thus far it would be better and safer to empty the dam, use the money you were going to waste on a new thermal power station and dismantle the dam completely saving lives and giving access to the flooded land for game, agriculture and minerals.
There have been concrete stuctures that have survived onver 50 years without cracks, bunkers built in Germany are now a problem to remove destroy as concrete continues to harden if properly mixed and prepared – there have been news items of the hardness of concrete left for years without any cracks.
If we have a multi span concrete bridge that develops a crack we close the bridge and replace the span as there is no way to repair a crack in concrete as it relates to a problem in the manufacture.
Those like Qwen above try repairing a crack in concrete at home drop it and see what happens – it cant be maintained or repaired to original strength, it will fail at the crack.
The only thing that is correct is we need consultants from overseas to advise us but I maintain the best course of action is to drain the dam and rebuild it in a stronger place or simply dismantle it to save lives and spend the money on a new thermal station.
It will fail eventually, and due to weakness on the dam wall and side support rock.
With concrete structures made properly and well supported they can as they are in bridge be suspended in air so erosion is not a factor that made it move and crack.
There is need for engineering expertise that is certainly not there at the moment.
It is obvious that the panic has set in. The ZRA has no choice but to say that there is no need to panic. Hopefully this wake up call has come in time and disaster will be avoided. There is no smoke without fire. The smoke is there. All we have to hope is that they take this seriously and stop the fire. Any holding structure of the level of this wall starts developing cracks then you have to say, something is not right. As the 2012 report when Mangoma said “I repeat that the wall on the Zimbabwean side is weak and requires anchoring and this is being attended to.It is something that is high on the agenda because without the dam wall you really have nothing,” This shows that reports are true if they were discussing it then. This repair should have been done without all this coming to the public in it’s present state. What difference would it make if it happened next week, next month, next year or in five years time. This is a wake up call.
My goodness there is nothing new.
Kariba was a bad plan, the side wall rock is friable, movement will cause cracks, over a decade ago it was considered by a team of engineers.
1. the siltation was at a critical level and this constituted unplanned extra weight and pressure on the wall.
A design was undertaken for a method of de-siltation utilizing a gravity suction method on the basis of a pool cleaner. Funding was unavailable so it was put on hold.
This also would help the turbines as additional silt passing through save was causing unnecessary wear.
Thought was put into strengthing the side wall area but the concern was the friable state.
The latest concern of erosion is simply inexperienced engineers looking at water flowing through the gates and imagining what a hosepipe does in the garden.
It is a difficult and expensive problem and may even need another dam wall constructing in front of it for safety, not an easy task, but possible.
Again the idea of putting addition turbines in was thrown out oat the time for safety reasons.
Of course the new engineers with 0 experience know better and announce they have this new brilliant idea of getting the Chinese to put additional turbines in.
It were better and safer to spend the funds on a new thermal power station or the expansion of existing ones.
Why was this bad idea let to stand for so long if there have been people who have long known it to be so. Why wasn’t any contingency planning done for a time when the bsd idea became a threat.
A good point the team I worked with looked at itv and the cost and at thetime without funding there was no solution. Presumably the river authority continued to cover up the problem because as inexperienced engineers were put in control they couldn’t get their head around the size of the problem. One earthquake and its gone!
We did look mainly at de-siltation and designed a method to attack the problem but again no funding and the current team from reports are attacking the problem backwards, which will be disastrous.
I personally was shaken at the decision to expand the power station, obviously one not made by a competent engineer aware of the risks.
What about all the other dams in Zimbabwe. The commercial farmers who built them are not there to maintain them. It is doubtful if ZINWA would take the responsibility of maintaining them.
To the layman as above it seems a simple job of maintenance filling in cracks which would not work.
Surprisingly, the art of making concrete has been patented by an engineer in Zimbabwe.
Those who think Zimbabwe backward will be surprise there are even world patents in the field of energy conservation – imagine, does this not illustrate how those with knowledge are no longer consulted.
Simply put concrete need vibration at a specific intensity and frequency dependernt on the aggregate as illustrated at a trade fair in Bulawayo, confirmed by CSIR in Pretoria AND DESCRIBED BY Prof McKecknie, civils, at UZ as a major breakthough in the building industry.
Without funding the invention has remained unutilized – and simply a patent.
Currently, and in the past, concrete was vibrated at one speed and intensity and pokers were identical, hence cracks and the collapse of concrete structures during earthquakes.
CSIR tested products vibrated correctly and classified them as indestructible, displayed at the Trade Fair along with the certificate.
A demonstration was conducted illustrating that utilizing current vibration equipment can actually separate particles causing cracks and weakness.
Ask any civil engineer locally and he will almost certainly not know what you are talking about such, is the state of our civil engineers, a disgrace when at local university they are not taught of local development affecting the world.
The designer simply won the award for design at the Trade Fair adjudicated by engineers.
Apolitical, what are you on about? So what if some design won an award at the trade fair? The talk here is about the Kariba Dam wall.
If you don’t understand please research you wont have a heart attack it will actually do you good to learn.
The dam wall is about concrete and cracks are mentioned which leads to development and the negligence of junior inexperienced engineers – follow the story now?
FACT. Aggregate/sand etc. is all a differ constituency in Zimbabwe it differs over a hundred meters or less so the method of making concrete varies and the world has yet to develop vibration equipment that is adjustable to cater for any aggregate. The first attempt at this was in Zimbabwe which success was verified by the CSIR scientific research station in Pretoria.
Apolitical, you are well versed in this work and quote technical issues. Please go to Kariba and assess and give us a true report and take that UZ person with you for back up. No Casino, no fishing only facts please as these other guys are now backtracking and we really do not want to loose our dam.
Unfortunately, the prof refered to is now deceased. However what I try to encourage is that people research themselves rather than comment without a clue.
I mentioned the concrete patent, its very easy to research we have a local patent office and there will be records from Bulawayo Trade fairs.
Thing is what I write is fact and the way to encourage is give the opportunity to doubters to research and verify.
This hopefully will create a new bread of journalists who research lest others do it for them and leave them without a job, as it should be.
This political speaks too much hstory from the Rhodesia Herald. Unomboita basa rei munhu anongonyora so much on every article in the papers? I bet your employer is not getting value for their money unless uri muCIO where that in itself is part of the job!!!
I don’t think I have ever mentioned any thing from the Herald – what I say is from personal experience and if you open your mind and research you will learn and discover the correct information.
What personal experience? Are you involved with maintenance work at the wall? Bottom line is, there is some maintenance work that needs to happen. Your research does not shed any light on it. If you actually go back to read the acres of stuff you wrote on this issue you will find that it poorly written to the extent of being meaningless. So, your research is of no use to anyone if you are not able to write it in a way that people can understand.
The issue is quite simple. Maintenance work needs to be carried out at the Kariba dam wall to avert a disaster and money has to be found to do it.
How to try and look like you know little!
The issue is very simple to one that has neither expertise or knowledge.
No one is saying there has to disaster, if proper notice is taken of past assessments then decisions can be made but if we have some one who can only talk about saving and averting a catastrophe then we are in gods hands.
Yours is exactly the kind of assessment we don’t need.
Its not as simple as filling cracks in your home – you perhaps should stick to opinion on this.
This Apolitical is politician so what do you expect from him,bottom line is the no money to loot they trying everything to get it. Everybody now knows wat happens behind those Govermment walls, nobody will ever donate a cent, by the way those helpful people who transported our stranded loved ones from tokwe dame been paid their due?.
@Madlanduna There is a real problem with this mentality you can point to a car and say this is a car and even when run over he will still say it doesn’t exist. Please research and learn.
@Apolitical-I do not agree with you when you say vibration mixing of concrete makes it 100% perfect because When I was in Japan a few years ago one of their highly qualified nuclear power station engineer told me that their stations were all weather proof and safe.I said to him nothing is man-made is perfect but he did not believe me until after their destruction by the earthquake
In order to achieve a patent it has to be fact.
Please before making descisions research and you eill find out that the reason for the collapse was lack og=f knowledge of making concrete.
Those issues and others are what stimulated the development.
Its relatively easy to verify, look at past newspapers of the awards at the Trade Fair search at the patents office.
Its the same story with all patents when something is patented others say they don’t believe it because they didnt think about it first.
You will note I didnt say maybe I quoted it as a fact.
This is why why there was investigation of the wall at Kariba I consulted to Prof Harlen the then CEO of Zesa and a board member of the world utilities committee.
SoRry I didn’t answer your whole statement.
I said the velocity and intensity of vibration if correct will make concrete indestructible during scientific destruction tests and this is fact check CSIR.
I also said it varies with every aggregate even a short distance from each other.
Civil engineering has been negligent in that it was and is engineering fact but because there are no machines with the capability they say the ones available will do.
Its a shame you didn’t visit trade faide where for doubters we illustrated aggregate separating at the normal vibration – the idea of vibration is to remove air pockets and water making the mix solid and unlikely to crack.
If there cracks then either the design ids wrong or the concrete wasn’t mixed correctly.
After getting a lesson on concrete this not being an Engineering forum the matter at hand is the question is there something wrong with the dam wall? There obviously is since the matter keeps on coming up. The next thing is what are they doing about it. @Apolitical how they repair it most of us don’t care .What we care about is are they able to do it or not. As you say layman,(someone without professional training in the subject area) you want us to research. I for one am not interested in Dam walls until they threaten my fellow countrymen and wild life. All we need to know on this forum is are they going to do it or not. If my house develops cracks I call someone that is qualified in Masonry. I take his advice on what to do. I don’t need to research. We don’t need the knowledge here. We need the solution.
The solution is, given the prognosis I personally would not have attempted to build a dam there in the first place.
The solution is to spend more money than the dam is worth on international consultants and remedies that are at best a gamble or gradually decommission the wall draining the dam.
It is unlikely based on consultants reports that any investor will want to know.
If no huge investment comes up decommissioning is the best alternative.
What I was meaning is that before publishing an article or articles it were better that the journalist got expert opinion or did some research.
Clearly from some statements made those in charge have no idea of the complexity of the issue.
It does involve public safety and loss of wildlife – its extremely doubtful whether any answers can be accessed locally.
@apolitical: I am following this discussion with great interest, partly through passion because I spent my entire teenage years living on Kariba from ’63-’69 (during school holidays) and for me it is the most beautiful spot I know in the world. And partly because without Kariba I believe Zimbabwe would be utterly doomed, at least in our lifetime.
Before Kariba was commissioned our Country’s power was provided by the Wankie coal mines, as far as I know. In those long-ago days, however, the population was about half of today’s, local industry and manufacturing were almost non-existent(the enormous spurt mainly being thanks to worldwide economic sanctions and thereby necessity owing to the ”bush war”)and much, if not most, of Rhodesia was not ‘on the grid’. Ironically, although I lived on Kariba from the time it started providing the much-needed hydro-electric power to the nation, Binga at the western end, my home, relied on diesel generators, gas, paraffin and candles for lights and power. Electricity was available there only many years later.
But I digress. The point of my post,’apolitical’,is that I refute many of your assertions. I bow down to your apparent superior knowledge of concrete and suitable locations for dams. HOWEVER: 1)I also knew Professor Harlen and I should like to have known HIS views on Kariba Dam. I certainly never heard any. Can you enlighten me via websites?
2) What evidence do you have that it would cost more than the dam is worth (and how do you equate its worth?) to consult international engineers about its condition, maintenance and remedies?(Besides which, it is surely true that international engineers have always been involved in consultations and on-going maintenance?)
3)If Kariba were to be ‘drained’, as your most feasible scenario, where would Zimbabwe’s power come from? Are you one of the madcaps who advocated a dam along the lower gorges of Victoria Falls? Sure, the basalt rock may be more resistant to erosion but the concrete dam would still be vulnerable. And at what cost to Zimbabwe, both financially and environmentally?
‘apolitical’, please put your thinking-thinking cap on before you commit your thoughts to outer-space.You might have more credibility if you were to give us your name so that we could check out your credentials.
I never take muy thinking cap off!
Here we are in a nation where two thirds is covered with cosal much of it friable and useless for export.
We conder dams covering more land up as the obvious solution – true there ids a need to put thinking caps on when even the non engineering condsider this. Its really about common sense – with thermal power stations friable coal can be used up creating more available land and export of power which is easy – this is the very obvious future – cant understand why common sense cant prevail. If we concentrate on thermal power stations we have sufficient coal to provide power for the entire southern african region for the next 500 years from Sengwa alone – with hydro power that will not happen, we will never produce enough for ourselves.
Like others, Angela Wigmore thinks of social advantages which she puts ahead of devepopment and logic. I agree Kabiba Dam was an achievement the rock was so friable I thought at the time they would never complete it.
There will be reports by Prof Richard Harlen at Zesa because the subject was discussed many times. With respect Angela why would he discuss it with you when you are so obviously not in the technical or engineering field.
Its a battle in comment scenario to discuss engineering and like most engineers generally discuss engineering problems with their counterparts.
‘Its extremely doubtful whether any answers can be accessed locally’, UUUHHH
,Apo, looks like we have gone full circle again.
The work and research has already been done by some of the best – we now have inexperienced engineers putting their oar in trying to reinvent the wheel, which will end in disaster.
We don’t have many, if any, consultants locally who have ever built the size of dam as at Kariba, this is why I say we will need expensive consultants from overseas to do a proper feasibility study which I feel will not be positive.
The easy way to explain is to liken some of the problems to a brick stuck to cardboard hanging from a clothline in the rain and trying to stop the cardboard from tearing whilst putting more weight on the brick. This explains the side walls and the friability.
Hey people I have warned you about responding to Apolitical he/she is purely there to annoy you & sidetrack you from the real issue which is the incompetence of the ZPF government. Please ignore this person who has made NINE comments on this article alone!!!
@Saddened -I hate having to address the sick with one subject that a change in government will save the dam. – you need serious help if you believe that.
As a matter of fact Kariba was built pre-independence. The local media hailed it as one of the largest man made dams in the world and a place for boating/fishing and drinking beer.
Considered a first for the then government – one the huge mistakes of thinking political all the time as above.
In fact it was a very stupid idea as the rock was simply not strong enough to support a dam.
They saw a George and said lets put a dam here and that was that devoid of any serious engineering ability.
It’s like saying the Government of that time was stupid in making roads that have developed potholes. Do something man with all your knowledge you claim you have on dam walls.
Small axe you need some life experience before you write, your logic is non- existent.The politicians were so strung up with the political achievement as most are, that they didn’t research properly – even their choice of the architect was suspect, Kariba is the only one he designed still standing – history speaks for itself.
If you build something badly then the blame rests on you, and yes it applies to all building and construction that fails due to shortcuts and lack of proper technical planning.
If you buy a car and it fails due to a manufacturing fault it is recalled by the manufacturer you don’t blame the person who inherited it.
Like the National sports stadium….
Anything not maintained for 50years will eventually collapse. It is a matter of time. The Harare to Beitbridge Rd finally gave in. There is no yellow lane. Trees are actually growing on the yellow lane. So the ZRA Engineers must quickly rectify whatever fault there is. This is now crisis management. I hope maZambians can assist us Zimbabweans. We are good for nothing. Useless buggers and crooks.
I would have to agree with Small Axe the Dam wall is not the only structure that has been neglected over the years. The sewerage system in Bulawayo and Harare is on the verge of collapse. The water distribution system and water quality country wide needs serious attention. Roads are in a terrible stage. Traffic lights, need I go on. Anybody that thinks we shouldn’t complain is not interested in democracy because that is what you do if a Government is under performing.
@ apolitical. Remember technology is an evolving thing. The reason for research is to improve on what is there and to discover new ideas, designs etc. Whatever you said about concrete vibration and the patent is something that came recently. The question is how can someone apply the knowledge in solving the problem at Kariba? If there are no machines/equipment that can vibrate concrete to the desired level the other question is what makes them unavailable? Is it lack of technology to manufacture them or they would be ideal machines requiring lots of energy input for them to achieve the desired work – rendering them impractical? If the vibrators are available, how will you vibrate the solid concrete in the dam wall? I agree with you that a new dam wall is required where you can probably suggest application of the new technology but for now we need a solution to the current problem. By the way you are suggesting a new wall downstream of the current, is the rock more competent?
The wall may be built on weak rock/foundations but I believe the designers considered the bearing capacity of the rock and other geological factors not only a suitable gorge. Remember you can still build a structure on very deep black cotton soils provided you construct a suitable foundation (piles, raft etc) and cost comes into play also. The rock on which the Kariba dam wall was founded may be weak but can sustain the stresses imparted to it by the wall. You can design a structure to take earthquake loading but there is always a limit to the amount of loading beyond which the structure cannot tolerate. You also cannot control geological movements occurring at Kariba and elsewhere on earth. These are natural and may be some of the causes of the problem(s) at Kariba besides increased pressure due to siltation. (But probably the designers considered the later). If there is relaxation in confinement to the founding rock at Kariba due to lateral and or vertical earth movements, there is bound to be lessening in bearing capacity resulting in failures noticed now. Yes there is need for detailed studies into the causes of failure(s) at Kariba Dam Wall before a remedial solution can be proposed but at the moment let’s not blame the designers and builders before the outcome of the studies. Remember we also learn from previous design mistakes (chakatanga ndicho chakachenjedza) and that some natural events like earthquakes can cause structural failure and their occurrence cannot be blamed on the designer or builder. No structure can withstand the extreme force of nature and no man is 100% perfect even in structural designs. Only God. Also let’s not be too theoretical about concrete. You cannot produce large volume concrete that is 100% homogeneous in consistency. That’s why there are factors of safety in design.
The only one under performoing rihght now is you. You need to think logically before you write.
a concrete wall is not like a car engine there’s not a lot to maintain if its built correctly.
If we had to maintain concrete then we would have to demolish houses to replace concrete foundations, take concrete skyscapers apart and a whole lot of stupid things.
The wall is not failing due to bad maintenance that’s a joke!
The siltation is bad but much the same as the dam on the nile and elsewhere, they are still thinking hoew to desilt dams once its built they don’t continue with things like that of prime importance. I think Prof Harlen was the first to bring it up.
There is a serious need for people to understand the problems of siltation – growing crops next to a river building lodges and hotels on the banks, the many things we do. Factually to give you a clue at the extent of the problem – we hear of the Zambezi flooding, did anyone know there is a massive 500 million tons of silt that needs removing between Tete and the coast in order to prevent this. This gives an indication of the size of that problem alone and the weight of silt against the dam wall.
There you go again. I am not performing at all because I am not a Politician or an Engineer. In what I do I am performing very well thank you. I run my household and business better than Zanu runs the country. That is where you will never excel because you are scared to call a spade a spade because that spade gives you patronage. You also think everybody else is stupid but you.
Silt is solid and does not behave like a fluid, therefore the pressure from the silt is largely vertically downwards and not horizontal. Its impact on the dam wall is not all that great.
The issue at present is the large hole below the plunge pool — regular maintenance could perhaps have reduced this.
A good attempt but you failed – silt or mud is combined with water and heavier therefore more weight on a dam wall – common sense?
You cpould also use your same argument for water in that water rests on the world as well there is always side pressure its like saying if a floating objects hits a dam it wont do damage because it effectively rests on water.
I wont charge for the lesson in common sense. You dont just have to learn in science you have to learn how to use the information.
So called erosion
As an after thought the river has been there since time began there were rapids through the George before the dam was built reducing the river bed to rock – what has eroded is the mud or silt that built up next to the outflow.
There are now silt bars in the river down from the dam wall with sharp sides – should we perhaps maintain them as well.
Any suggestion this problem will have to be also solved by the Chinese, but in 50 years time when it gives trouble blame it on them too ???
Just fix it, build a butted water race from the sluice gates and there won’t be a plunge pool and the wall will have a new buttress support. There you are, fixed ! Pay $10 into my private bank account, thanks.
For the other sewage and running water problems I think the town councils personnel are to blame. Some people have been born since running water in the towns has stopped and reinstating this would be considered improvements for them let alone repairs. Pambere ne Zimbabwe !
@lost birthright no one would disagree that the councils have to shoulder some of the blame but at the end of the day it is the Government that has to create the conditions for these services to exist and the councils will then be accountable to the Government. This will never happen here because the opposition is supposed to be in control of the councils so the rulers will always put a spanner in the works, hence there were calls for the Mayor to resign in protest during the Harare Town clerk saga. @ Small Axe you are totally correct. Apolitical is just another commentator on this forum and a lot of his logic is also non existent. You have heard him elsewhere saying the people in the diaspora are criminals???
Fair comment Doctor do little – It really is amazing that the problem at Kariba hasn’t been taken by the horns and tackled professionally by the Zambezi River Authority (formally CAPCO). Grouting has been going on for decades, but I think this task has also fallen away. The dam is an investment which nobody in government appreciates. It is a matter of too little too late if the disaster occurs. Best I go and enjoy my last Tiger tournament this year !
All the best technology to put things right have left the country that are able to resurrect the city amenities. It won’t be long before expats will be top of the list whether they like it or not.
some in the diaspora are criminals in jail in both the UK and South Africa its common knowledge authenticated, other ran from prosecution locally, others saw a way to get hand outs in UK and sponge – honest ??. Can’t help if you don’t like facts they wont change to suit you.
Cant expect someone that simply imagines to know I suppose, good luck ion your dream world.
Cant imagine what your comment has to do with Kariba but then I suppose its simply a reflection on your thought pattern and mind.
How government be blamed for councilors non performance and them not cutting their salaries?
@Apolitical-you have admitted that if the velocity and intensity are CORRECT which is impossible to achieve in real situation because you have to ensure that the mains you are using has a stable frequency and less fluctuations to have a very stable rotation.How do you propose to have a 100% pure ZESA supply during your mixing periods? As far as I know its impossible to have any made-man system which 100% perfect and this would make your concrete mixture very dense to handle.Please give me your theoretical formula you used to come out with these results.
The patent was demonstated publically at a trade fair and produced product tested by CSIR.
You may have doubts but you need to go back to electrical theory on constant speed of electric motors an absolute theory ewhich doesn’t alter – not even Zesa can change something absolute. Hence motor speeds are printed on electric motors they don’t state unless changed by Zesa in Zimbabwe
Its not a theory – a theory is almost impossible to patent as for example in the EU there are 20 different engineers involved whose job is to criticize and disprove engineering patents. International patents are not easy, I remember a delegation of 4 rngineers from the EU vising to find out how we managed to do it prior to the ARIPO patent being established locally.
Because they could not there was reaction, they formed the ARIPO patent system controlled by the EU and a path virtually impossible to ascend to an EU patent.
The third world are not supposed to hold patents, its supposed to be the other way around.
However there are a few ex Zimbabwe patents that succeeded, I know of no ARIPO patent that succeeded as an international patent.
So if we have synchronous speed and we factually do then concrete can be mixed uniformly in large quantities.
Its no longer theory taught in engineering faculties its now fact. That was the breakthrough described as such by the civils prof at UZ.
I think he is referring to me.
A very very confused man.
I would like to draw everyone’s attention to the prophecy given by one of our very own prophets,Emmanuel Makandiwa, in January 2013 when he said he foresaw the collapse of a ‘great” wall with people being subsequently plunged into darkness and mourning! Let’s heed the prophets of God in our midst! Food for thought?