4. Construction Design considerations

Figure 13. Viewing the building system from the north-south section

Figure 14. Viewing the building system from the east-west section

4.1 Construction system used for Women’s house:

 Here we are using Load bearing masonry construction using a ground beam made of mass stone ,sand, cement construction. This type of construction system is very adaptable in that area and some of the knowledge about constructing beams and roofs will be helpful to the community.  Construction materials and calculations are provided in the costing table.

4.1.1 Capping beam and two footings in activity room shown in floor plan.

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4.1.2 Wall to footing section.

 Termite land treatment using soil applied termicides as a conventional method using liquid before the construction has been done. (Waldvogel & Alder, 2009)  Here the capping beam is made of 1:4:8 ratio of cement, sand, aggregate. Capping beam is very big because of unreinforced construction.  In the area of baghere village some of the resources such as sand and aggregate are very cheap and available.  Providing efficient ground beams makes earthen walls structure disaster resistant and reduce risk of wall overturn or failure in the earthquake disasters.

4.1.2 Detailed wall section including roof and window.

4.1.3 Alternative roof system using shingles or clay roof tiles.

 Mud bricks are used for the load bearing wall which is available in the baghere village. We can involve some of the local people to make this construction system as it is simple construction. Material is very sustainable and an approach to make green building.  In the mud bricks less than 5% of cement is added and contains water, clay , and other alkalis such as asphalt to make it more durable in rainy seasons.  Mud brick construction in Africa is around 60-70% accepted and very low cost, low embodied energy and provides high durability with using plaster outside. (Adegun & Adedeji, 2017).Mud bricks can last up to 30 years.  Outer wall finishing is done by plastering and painting as it was important to waterproof the masonry system. Some of the considerations from old techniques were mud slurry applied on the inside of the house which contains mud and cow dung.(Mud Brick, YourHome, 2002) Sometimes this slurry can be used as a surface finish for the plaster instead of mortar.

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 Maintenance of the mud brick walls should be done by rendering the walls from outside and inside where needed. Materials used for rendering are cow dung mixed with water, sand, and river silt.  Building maintenance should be done every year as it has no cost and should be done in an appropriate way as before rendering, holes in the wall and gaps should be filled with the paste and then layers of the paste should be applied on the wall. Color coating can be done after this rendering to protect building for more than one year.  In the activity room area, we are making bricks made of clay and aluminum waste which is available in Senegal mixing this tuff with 4M NaOH to get maximum results. We will make bricks using wooden moulds. Composition of the material brick was CaO–Al2O3–SiO2 with cementitious material. (Diop & Grutzeck, 2007)  Some of the sample tested mixing of alkali concentration 12M NaOH cured at 40° temperature were better than which samples cured at 80° temperature.

 These bricks are sun dried at 40° temperature and need 28 days to get maximum compressive strength. These bricks have very low carbon emissions and can be a business opportunity for community to generate income. Mud bricks dried out from sun will shrink before placing for walls so the risk of cracking in the walls will be reduced.  Brick made with this material is very energy efficient where energy is unavailable. Better for humidity and high temperature villages such as in Senegal.  Some of the advantages to build mud brick construction in community were high thermal mass and high fire resistance than other conventional construction systems.  One of the alternatives for roofs was to use clay roof tiles as baghere village is very hot in summer the GI sheet is highly conductor of heating and cooling but roof load can be increased due to this material. Costing is done for the GI sheet as it is preferable by community.

4.1.4 Queen Post Truss design for roof

 Roof structural was based on queen post truss as the width of the building was 9m. (Queen Post Truss, 2007)some of the advantages are they are reliable and very low cost. Where in the activity area there is no ceiling provided so it can look attractive from outside. Roof sundries such as screws, u-strap, cleat, nuts, were imported materials as not available in the village.

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 Wall plates should be provided for the support of the roof structure. Roof overhangs with eaves gutter to collect the rainwater. Rainwater pipes connect to the downpipes which connects to brick rainwater harvesting tank. Roof overhangs are better as it protects walls from the water.  Mineral wool is used as insulation and it will also act as vapor barrier as it absorbs water and material chosen is fire resistant.  GI sheets are used for roof covering as it is waterproof, very cost effective and reliable as a long-life span of the material. Bamboo in this construction will be used for outer plaster, paint and making roof.  Soffit, battens, and rafters should be made on site via community to have more understanding of the roof structure and to do upskilling of the community.

4.1.5 Bamboo scaffolding diagram

4.1.6 Bamboo scaffolding sectional view.

 Bamboo scaffolding is very common in developing countries and available at a very cheap rate at sh40 per bamboo stick. (Kiarie, 2014)  Using bamboo single layer bamboo scaffolding method, the height of the one bamboo connection should be 1.8m and length between two bamboo scaffolds should be 1.2m. (Chung & Chan, 2002)  Bamboo is very lightweight material and easy to transport and available in the baghere village.

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4.1.7 Front elevation for bamboo scaffolding used for working on roofs.

4.2 Gantt chart including five stages:

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4.2.1 Gantt chart

 Collaboration stage includes project briefs done by client and other processes such as conceptual and developed design are done by the core team and technical design are done by the structural engineer. Integration of core team(Architects, structural engineer, landscape designer, electrical engineer, mechanical engineer) and strategic team(Project manager, contractors) is very helpful for the performance of the project.  Approval stage of the women’s house will take up to 61 days. which is followed by site establishment. (PIENAAR, 2019)  Here we have provided that before working on site we provide some of the safety sessions to labor and community which we are involved in the construction process.  Gantt chart includes all the five stages from collaboration stage to post occupancy evaluation.  In the Bar chart, we also showed earth compressed blocks made for the activity room area that need to be made in 60 days. We need to dry them for minimum of 30 days to get maximum strength.  Activities such as masonry of bricks made with tuff samples were starting late but with other activity as it was finished to start activity in the Gantt chart.  Post occupancy evaluations contain some of the reviews from client and design team to evaluate the outcome of the project brief. Analyzing building layouts and functions of the rooms is helpful in the future project considerations.  Some of the energy use of the building should be surveyed as here we are using mud brick construction that has low carbon emissions and having insulation provides better thermal comfort to the building.  Post occupancy evaluation in some projects is done based on a contract for up to 1 year to get maximum output. (RIBA Architecture,2016)  This project should be built in 351 days as per the chart.

4.3 Costing of the women’s house in Baghere village:

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