Johnson Drennan 3501 Fall 2008 Web

MASONRY

STRUCTURAL MATERIALS RESEARCH CATALOGUE CONTRIBUTORS

Marshall Drennan and Cody Johnson

STUDIO 703

ARCH 3501 - ARCHITECTURAL DESIGN STUDIO 4 COLLEGE OF ARCHITECTURE TEXAS TECH UNIVERSITY - FALL 2008

MASONRY History - 00

History and Architects

History

MASONRY History - 03

Hisory of masonry

Masonry is one of if not the oldest style of construction. The pyramids and stone hendge are thought to be the oldest existing structures in the world. Masonry has been used throughout time for nearly every precident and has preformed many different uses.

History

MASONRY History - 04

Hisory of masonry

Masonry has preformed many different uses throught history. its solidity has made it a form of protection such as in the great wall of china, while its compressive force has made it used to erect tall alters to gods.

The arch

MASONRY History - 05

Hisory of masonry: the arch

The arch is a construction form that transitions forces outward through its form to its base while in compression. the romans where one of the first cultures to use and master the form of the arch and its spanning capabilities. Traditionaly arches where always constructed out of masonry. In order for masonry to span its greatest distance it must b built in the form of an arch.

Architects

MASONRY History - 01

Hisory of masonry: architects

Antonio Gaudi was an architect and master mason in spain. His works are constructed entirely out of masonry. Among his most famous works would be Sagrada Familia. Which is still underconstruction after 100 years.

Architects

MASONRY History - 02

Hisory of masonry: architects

Eladio Dieste was an architect and master mason in uraguay in the late 20th century. His design for the tower of the obrero church is what gave us the design for the cantalivered stair. Dieste has taken contemporary masonry to a new level with the works that he has created.

EQUIPMENT

MASONRY EQUIPMENT - 00

Structural Research Materials Catalogue

Materials Necessary for Masonry Construcition

Brick

MASONRY EQUIPMENT - 01

There are many different kinds of bricks out in the world. All are good with compression but some are stronger than others and some are even designed differently. The differences can be caused by many different factors such as: the chemical composition of the clay used ot make the brick, how hot and long the bricks are fired, and even how they are cooled. Also, some bricks are made with holes in them to make them lighter or for a place for a tensional steel rod to pass through the structure.

Materials Necessary for Masonry Construction

For our project we chose a simple paving brick that is smaller than normal brick which allowed us to make smaller structures even though we were using real brick blocks. Being able to use the real bricks was a very good learning experience.

Mortar

MASONRY EQUIPMENT - 02

Materials Necessary for Masonry Construction

Mortar is the glue that holds the masonry material together. Just like bricks there are many different kinds of mortar to choose from. The mortar that is used needs to be strong enough for whatever kind of load that it will be used for. Some mortars are only good for small garden walls while other mortars are specifically designed for enormous loads. The mortar starts out in a liquid state and has to dry to a state where it is expected to be just as compressively strong as the bricks it holds together. Also, some mortars dont have any sand which must be added later to the mixture. the ratios for the mortar sand ratio vary but in out test we found that 1:2 worked best. When adding water to the mortar mixture one only wants to add just enough to where if the mixture was stirred in the bucket it would be easy to stir but the mixture would not fall flat after the stirring.

Framework (Wood)

MASONRY EQUIPMENT - 03

Materials Necessary for Masonry Construction

Frame work could be made of a few other materials but wood is usually chosen. Wood is the preferred framework because ti is quick and easy to work with, especially as a temporary structure. The framework is what is required to hold up whatever one is building so that the mortar has time to dry. In this case of an arch the framework is also necessary to hold all the parts up until the structure is complete because an arch requires all parts to be in place before it can be successful. Wood also comes in many shapes and sizes (refer to the wood chapter for specifics). For larger arches the solid wood support is not recommended and never really used. Instead the frame is made of wood trusses with an outer curved section to hold up the masonry work. Once the masonry has been placed and the mortar has had time to dry then framework can be taken away leaving a very strong compressive structure.

Re-Bar

MASONRY EQUIPMENT - 04

Materials Necessary for Masonry Construction

Re-Bar is metal tubes that are used to give a compressive material such as mortar or concrete tensile strength. Usually the Steel is concealed which gives an aesthetic quality to the compressive form making it look as though it is defying its fundamental propertires. Re-bar is tied together using small thin strips of metal and a special tool almost like a twist tie to seal the bread wrapping. Re-Bar is definately not always necessary in masonry construction but is used at times when needed.

Tools

MASONRY EQUIPMENT - 05

Materials Necessary for Masonry Construction

On our first attempts at masonry construction we tried the use of wooden sticks to stir and apply the mortar. These worked okay at first but then we began to mix larger batches and need better application. The sticks often broke in the mixing of the mortar and worse yet when trying to apply mortar to the bricks it often prefered to stick to the wood. We then invested in a trowel. This is a tool specifically designed for masonry construction and mortar application. The trowel, even though not a mixer, worked very well for mixing the mortar because it easily went to the bottom of the bucket and would not break. But, best of all the trowel was perfect for applying mortar. We could gather a large amount of mortar on the trowel and it would slide right off like it was on ice. The trowel made work much easier, quicker, and more efficient.

Tools (Cont.)

MASONRY EQUIPMENT - 06

There needs to be some kind of container that is used to mix the mortar on large scale projects it isnt usually a bucket but a portable cement mixer that keeps the morter ready for use and mixed easily by just pouring in the ingredients. However, we chose to go the hard way and use a home depot five gallon bucket and a trowel. there are also attachments to a drill that could be used to mix the mortar in a bucket or wheel barrow for you.

Materials Necessary for Masonry Construction

The last tool necessary is the special tool designed to twist the re-bar ties. The re-bar ties have a loop on each end and you thread the tool through both loops and then just spin it around until it gets tight around the re-bar. We had to be careful through because the tool was so efficient that we broke many of the ties by spinning them too tight.

Process of Construction

MASONRY CONSTRUCTION - 00

Structural Materials Research Catalogue

The Method Used in Masonry Construction

Buying Materials

MASONRY CONSTRUCTION - 01

The Method Used in Masonry Construction

Construction materials seem cheap at first but when you end up having to buy a whole lot of them the cost really adds up. Home Depot and Lowes dont ever have any “extra” bricks to give away. However, we found out from Fred that Acme and other brick supply stores around lubbock will practically give away there left overs or wrong color bricks, especially to needy architecture students. Anyway, finding leftovers and asking politely is a much cheaper way of getting small amounts of construction material than going to a store such as home depot.

Making Formwork

MASONRY CONSTRUCTION - 02

The Method Used in Masonry Construction

The Frame work is a very important part of the construction process. we used plywood, two by fours and re-bar in our framework. We cut the plywood with a jigsaw once we had drawn on the catenary arch adn then connected the two sides with two by fours running through the center. We then made stands for the cantilevered steps. Also, we had to cut our strips of re-bar to size so they would fit inside the steps without poking out.

Preparing the Site

MASONRY CONSTRUCTION - 03

The Method Used in Masonry Construction

For our construction sites we chose open spaces that were relatively out of the flow of traffic, clean, and especially that were flat and level. We then cleared away all debree and put down paper under our projects to protect the ground from falling mortar and so that we wouldnt actually attach our projects to the ground. Picking the site is very important because you dont want the project to be too succeptable to the weather, or people who might intentionally knock it over.

Mixing the Mortar

MASONRY CONSTRUCTION - 04

The Method Used in Masonry Construction

The mortar was one of the most difficult parts to get right. First of all the sand mortar ratio had to be right, but in the structural mortar which we used at the end luckily the sand was already mixed in. To mix the mortar all was had were hand tools such as a trowel and wood sticks. This really wore out our arms because of all the difiicult mixing. However towards the end of the projects it was almost insticnt on how much water to add and exaclty what would be the right consistency for the type of brick laying we were doing.

Laying Brick

MASONRY CONSTRUCTION - 05

The Method Used in Masonry Construction

Laying brick was more tricky than we though it would originally be. One key is to make sure that there is plenty of mortar so that the brick actually pushes it out of the sides. This ensures that the whole brick on the bottom is covered. The trowel also works best so that the mortar only sticks to the bricks instead of what you are using to apply it, which can take the applied mortar right back off the brick. we were trying to use our hands to make sure that the bricks stayed clean but that is something that comes better with experience.

Wait to Dry

MASONRY CONSTRUCTION - 06

The Method Used in Masonry Construction

It is important to make sure that each part is properly dry before taking any of the formwork out. for the arched part we waited until it was about mid way done through the drying process of 24-36 hours and pulled the formwork out so that the compressive forces could get dried into the mortar. But, we waited until the bricks were completely dry before removing the support for the cantilevered step because we didnt want it to be able to move at all. also the steps have very thick applications of mortar which will cause a longer drying time.

MASONRY FAILURES - 00

Failures

Attempt one

MASONRY FAILURES - 01

Failure attempt one at arch construction

This was our first attempt at an arch. This blind attempt ended in a failure of the arch due to the construction technique. bricks where not allined in a fassion as to transition forces from the top to the base, there where no pinicals to hold the base of the arch from expanding and no definant keystone to contain the forces of compression.

Attempt two

MASONRY FAILURES - 02

Failure attempt two at arch construction

Attempt two at arch construction ended in a failure. Learning from the first arch we built in a mannor that the forces would run down from the key stone to the base. This arch was also constructed in the cantinary style. This attempt failed due to the absense of a pinacle to hold the base from flairing out under pressure and from being built on its side and then stood, the standing required forces to be applyed in a way that the form was not ment to withstand therefor busting the morter joints.

Attempt Three

MASONRY FAILURES - 03

Failure attempt three at arch construction

For our third attempt we constructed the arch on a standing framework. pinicals where also added so that the bottom of the bricks would not push out under compression. This arch failed due to a weak morter joint. the arch stood but once we applyed force to the top of the arch a morter joint in the bricks cracked and the arch crumbled under the pressure.

Corner detail

MASONRY FAILURES - 04

Failure corner detail of brick

The corner detail failed due to the type of morter uses. After the bricks had dryed they where able to be pulled apart easily. From this initial test and first construction with bricks we learned the importance of morter strenght in masonry construction.

Success Models

MASONRY SUCCESSES - 00

Structural Materials Research Catalogue

The Succesful Models that Led to our Final Project

Arch (Construction)

MASONRY SUCCESSES - 01

The Succesful Models that led to the Final Project

We finally had success on our arch. we were able to achieve this success by waiting 2 hours before we removed the formwork which allowed the mortar to have time to set up while still allowing it to dry under pressure. the other secret that we learned was to build it standing up with formwork instead of trying to cheat the system by building it on its side on the ground then standing it up.

Arch (Weight Held)

MASONRY SUCCESSES - 02

The Succesful Models that led to the Final Project

The arch was able to hold one of our classmates, Jasmine, with no problem at all. It could not, however, hold Marshall (230 lbs). The point at which it faled was the single layer on the top where it bowed at and broke at the mortar seems. We concluded that our final project woudl have pleant of strength with the better mortar and the thinest point being 5 layers of brick thick.

Cantilevered Step (Construction)

MASONRY SUCCESSES - 03

The Succesful Models that led to the Final Project

To test the cantilevered step idea we built a model and used rebar in between to layers of brick running diganollay through the steps. we chose this patter because it gave each step two pieces of re-bar going into them and then the re-bar would travel all the way to the other side to help balance out the forces from side to side.

Cantilevered Step (Weight Held)

MASONRY SUCCESSES - 04

The Succesful Models that led to the Final Project

The step was able to hold Marshall (230 lbs) standing on the ver edge of one of the steps no problem. Then i tried to jump on it and thats when it broke. We deduced that it would still be very structurally sound for our final project because the mortar was not as strong as the structural mortar and it had to dry during a day that saw eight inches of rain. the new steps are still standing even with people jumping on them.

MASONRY FINAL PROJECT - 00

The Arch Final Project

Design

MASONRY FINAL PROJECT - 01

Final project design of the structure

The origional design for the final structure came from this origional sketch of a cantalivered stair spanning by use of an arch. The cantaliver came from a design by Eladio Dieste (reference architects page) in which a cantalivered spiral stair case lines a tower. As we progressed in design the model progressed into an eight foot span at 4 feet above the ground. with stair steps up the sides and cantalivered stairs at the top.

Materials

MASONRY FINAL PROJECT - 02

Final project materials used in construction

For materials for the final project we used garden brick, plywood sheets to make the frame, two by four’s to create a brase for the cantalivers, rebar, and 80 pound bags of type S construction morter.

Preparation

MASONRY FINAL PROJECT - 03

Final project Preperation prior to construction

Prior to construction wooden framework had to be prepaired. Using the catnary arch we cut the main framework. Then four braces where constructed to hold the cantalivered stairs in place while their morter dried.

Construction

MASONRY FINAL PROJECT - 04

Final project Construction

After the initial framwork was erected construction began by laying one brick at a time and applying morter. The design called for a double layered arch with a flemish bond of bricks on the outside pinicals.

Construction

MASONRY FINAL PROJECT - 05

Final project Construction of the keystone

As the arch approched the keystone a single brick was too thin and two bricks where too thick. to properly have a keystone we had to cut bricks to the proper size using a hammer. Above the keystone the flemish bond continues from the pinicals above the arch to provide extra support.

Construction

MASONRY FINAL PROJECT - 06

Final project Construction of the cantalivered stair

The support braces where cut to exactly the height of the base of the cantalivered stair. Each step had rebar inbetween the morter and extruded away from the arch. Four butraces where placed at the base of the arch so that when weight is applyed to the cantalivers the arch would not fall to that side.

Testing

MASONRY FINAL PROJECT - 07

Final project testing for stability

After letting the morter dry for two days we removed the framework, to test we placed controled weight with our hands on different locations on the arch to make sure there is no structural failure. We then proceded to walk on the arch and it proved that it could hold the wight of a person.

Testing

MASONRY FINAL PROJECT - 08

Final project testing for stability

The arch proved to be stronger than anticipated and held the weight of seven men without any signs of structural failure.