Abstract
The paper addresses the stone waste produced as leftovers from the stone industrial activity in the Occupied Palestinian Territories. It discusses the idea of recycling the waste as an opportunity for developing alternative crafts in the Palestinian villages which are economically based on the stone industry. The proposed reuses utilize the techniques of casting and briquetting to create new stone models. These models aim at redefining the cultural and architectural role of the stone facade through the use of new raw materials: stone powder and gravel. The recycled stones would help turn the waste from an environmental and economic burden on the Palestinians to an opportunity that rethinks their industrial practices and their relationship with the landscape.
The paper initially explains the background that lead this research and presents experiments carried out by local designers, artisans and academic researchers as well as experiments I carried out as part of my graduation project. The aim is to point out the ongoing environmental and economic issues in the context of my interventions and initiate an open-ended research to deal with these issues through material design.
Background
My graduation project "Mountains reclaiming The Stone" questions the value of stone in Jerusalem’s cultural heritage by addressing the footprint of the stone industry on the landscape and the building practices today. The project puts the light on the environmental and economic aspects of quarrying practices in the Occupied Palestinian Territories overshadowed by Jerusalem's holiness.
Since the British Mandate on Jerusalem, the city has been perceived as a "precious rock" frozen in time. The preservation of stone, as the main vernacular building material in Jerusalem and a physical illustration of its holiness, has been mistranslated into the most rigorous cladding regulations in Jerusalem since 1918. Parallely, there has developed a large industry of stone quarrying and cutting in the West Bank, widely known as the “White Oil”. The destroyed hills of the Palestinian quarries construct the stone-covered buildings of Jerusalem and everything else that seeks to be part of the holy city.
Today the stone industry in the West Bank is facing many challenges gradually building on an economic crisis. “We are running out of stone” says the owner of Al-Waleed Company in Beit Fajjar town near Bethlehem, the largest industrial zone of stone quarrying and cutting in the West Bank. Moreover, the industry is mainly dependent on the demand in the Israeli market which constitutes around 65% of the total sales (Hashish, 2012). Nevertheless, the quarries’ and factories’ owners who I interviewed do not believe that this is the number today, not anymore. They say that most of their Israeli customers are shifting to the cheaper better quality Turkish and Chinese stones and not buying their products anymore. This is dramatically affecting the stone sector in Palestine.
Among many other challenges the industry is facing today, the issue of stone slurry disposal- a by-product of the water circulation used to cool the cutting machines in the factories- is one of the most urgent to deal with. The slurry hasn’t been systematically dealt with in anyway, rather is disposed in large quantities in open areas and directly affecting the agriculture and the health of the nearby residents (Beit Fajjar Municipality, 2018). The disposal of the slurry also causes extra costs on the factories who need to get rid of it on a daily basis.
In my proposal, I try to involve the stone waste in the construction industry in order to help reduce Palestinians dependency on the extraction of stone on the one hand by creating a temporary alternative to the natural stone and new industrial opportunities for the Palestinians on the other hand. To do so, I have looked through international and local research dealing with the issue of stone slurry reuse. Although not an expert in material design, I, as well, allowed myself to carry out experiments in stone waste briquetting, utilizing my architectural skills to reinvolve it as a building material.
About Stone Waste
The stone waste can be divided into two categories: broken pieces not suitable for construction and stone slurry produced by pressing the liquid slurry from the diamond cutting machines (mainly constituting of water and CaCO3).
The broken pieces are usually carried to stone crushers and turned into gravel in variable sizes (na’ima, simsimiyya, adasiyya and fuliyya) to be used in the construction industries. The stone slurry is not reused in any significant way, rather is disposed near the factories, inside inactive quarries, in agricultural lands and close to residential areas. A middle-sized stone factory produces around fifteen tons of slurry per day. In a year, around one million tons are produced in the West Bank from all stone factories in total. This amount is equivalent to around half a million cubic meters of pressed slurry per year (Joulani,2014).
Opportunities
In an interview with the geologist Dr. Taleb Al Harithi he mentioned possible uses of the stone slurry after processing it including fodder production, paper production (80% CaCO3+ 20% plastic), medications, polishing materials, etc. These industries could be very promising with great economic benefit, however they need technologies that may not exist at the moment, higher investment costs and more complicated logistics (Al Joulani, 2014).
In his paper “The Stone Slurry in Palestine from Environmental Burden to Economic Opportunities—Feasibility Analysis”, Dr. Nabil Al Joulani argues that among the different possible uses of the stone slurry, the optimum current solution that matches the Palestinian economic and environmental context and the challenges associated with the stone industry, is the ready-mix concrete.
Dr. Al Joulani mentions several reasons for the favorability of using stone slurry in concrete production. First is the practicality of the concrete as a basic construction material and the suitability of ready mix concrete for vertical construction which puts it in high demand. Therefore, the use of stone slurry in the concrete mix would be an efficient way to get rid of the large amounts of the slurry produced annually. Another important factor that puts in favor the use of slurry in concrete production is the fact that the utilization of stone slurry instead of sand in the concrete mix would conserve a non-renewable natural resource which is the sand. This will help create a new sustainable development engine in addition to getting rid of a heavy devastating environmental burden which is the stone slurry (Al Joulani, 2014). The only obstacle would be finding the technical tools and knowledge to make it applicable.
Local Experiments and Models
In Jerusalem Design Week 2018, the designers Avior Zada and Eliad Michali presented their new catalog of designed stones that can replace the monotonous stone cladding imposed on the architects working in Jerusalem. About 90 stones were hung on the wall, the composition of which varies, while their shape is identical as they were cast in the same mold. 80 percent of the composition is made from stone aggregates and powders while the rest are binding materials. One example is a stone made of stone powder from a quarry in Sa’ir, Hebron, and clay from a dismantled house in Agripas street, Jerusalem. The work is political and controversial as it mixes between materials that may be collected from Israeli areas and the Occupied Palestinian Territories (Riba, 2018)
They see their stones as models that may be mass-produced or even 3D printed to replace the natural limestone in the future. These models raise questions about what is “Jerusalem Stone”, a stone that no longer comes from Jerusalem, rather from the West Bank or even imported from China or Turkey nowadays. Are the stones they have developed more local than the natural stones which the building regulations in Jerusalem strictly demand?
Mousa Hureizat from Yatta, Hebron, has his own factory where he produces artificial stone with stone slurry from wet-cast concrete mixes. Artificial stone is usually made of white cement, sand and gravel aggregates with small amount of additives to improve its durability. He started his project 3 years ago when he came up with the idea to include the stone slurry in artificial stone production, after he saw what a great burden it causes to his family business in the stone industry. He thought he could help recycle the waste by developing an alternative model which not only looks and serves like natural stone but is also made of stone leftovers: the stone slurry powder. He began to add the slurry in very small amounts (up to 5 percent) in the concrete mix partially replacing the sand. Today, the stones he produces include up to 70 percent of stone slurry completely replacing the sand and gravel in the concrete mix. Mousa claims that the stone slurry-cement stone not only is made of a better homogeneous mixture with less possibility of cracks compared to regular artificial stone, but also is competitive in price and durability to natural stone.
In an interview with Mousa, he gave me three different models that he developed for my reference. The first is an artificial stone made of stone slurry (around 60 percent), small blue glass pieces and white cement. The glass is another type of waste produced in large quantities in the glass workshops of Hebron. Mousa hammered the stone face into tubza so as to reveal the blue glass inside the block. The stone may be used as an outer cladding material to buildings. The second stone is a tile with up to 66 percent of the stone slurry in the wet-cast concrete mix. Mousa also adds colors to create different shades and effects of the stone tiles. The third stone is a 1cm-thin concrete block curved into a U-shape. The stone is reinforced with glass fiber which gives it a lot of strength.
Throughout my graduation project, I worked on experiments with the stone waste in the Department of Ceramics and Glass Design in Bezalel Academy where I was hosted to work in their laboratories. My aim was to explore the potential of the stone powder and gravel as a raw material for the design of new materials which can be involved in the Palestinian stone industry.
The first experiment is associated with the specialty of the hosting department: glass. I mixed the stone powder with glass powder in four different ratios, filled them in a plaster mold and baked them in the oven at 770 celsius. At this temperature, there is a great probability that the stone turned into calcium oxide. The result is a very light material with tiny holes. The mixture with the highest amount of glass (75% glass, 25% stone powder) is the hardest model. The mixture with the lowest amount of glass completely came apart after taking it out of the mold. Although the material hasn’t gone through any physical or chemical examinations, the results suggest that it has the potential to work as heat insulator if it was further developed.
For the second experiment, I replaced the stone gravel in the concrete mix with stone pieces that are thrown away as waste after hammering the face of the stone tiles used for cladding. I created two models, one with smaller pieces and the other with larger pieces. I cut the surface of the block in order to reveal the stone pieces. According to the physical examinations that I carried out, the block with the larger stone pieces had better compression strength than the other block with the smaller stone pieces.
In another experiment I replaced the sand in the concrete mix with the stone slurry, an experiment that has been explored to depth by Dr. Nabil Al Joulani. I tried it in dry-cast concrete tiles and in wet-cast concrete blocks. The results are positive. Dr. Al Joulani’s experiments indicate that the slurry waste powder generated from stone cutting industry could be used instead of sand in artificial stone production with reasonable compressive strength and absorption compared to natural stones.
The last set of experiments involved the technique of compression to create briquettes out of stone slurry powder. I tried to compress the powder under high pressure of up to 120 tons. At the beginning, I compressed the stone slurry without any additives, and then added other materials such as clay and cement to help bind the powder together. Due to imperfect molds used for these experiments and the inaccuracy of work, they all failed. However, the technique of compression has great potential if used with the right tools and in the right settings.
In my graduation project, these experiments acted as complementary materials to my architectural proposal in Beit Fajjar, the largest Palestinian stone complex Southern of Bethlehem. My intervention proposes an economic and cultural renewal in an ongoing destructive economic activity in the town which is mainly based on the stone industry. In my proposal, I present a new model of common stone factories with areas for recycling stone waste and a research center for material development. The aspiration is to help reclaim Palestinians’ historic integral relationship with their landscape through new industrial and cultural activity. Instead of bringing new materials and technologies, the proposal uses existing materials, techniques and knowledge and rephrases them as a starting point towards the change.
References
- Al Harithi, Taleb. “Interview with the Geologist.” Nov. 2018.
- Al-Joulani, Nabil, and Nidal Salah. “The Stone Slurry in Palestine from Environmental Burden to Economic Opportunities—Feasibility Analysis.” Journal of Environmental Protection, vol. 05, no. 12, 2014, pp. 1075–1090., doi:10.4236/jep.2014.512106.
- Al-Joulani, Nabil. “Utilization of Stone Slurry Powder in Production of Artificial Stone.” Research Journal in Engineering and Applied Sciences, 2014.
- Beit Fajjar Municipality, “وثيقة الخطة التنموية المحلية لبلدة بيت فجار 2021 - 2018. (Local Development Plan of Beit Fajjar Town 2018-2021” 218
- Hashish, Maher. “صناعة الحجر والرخام في فلسطين (Stone and Marble Industry in Palestine).” Dubbel, 2012.
- Hureizat, Mousa. “Interview on the Utilisation of Stone Slurry Powder in Artificial Stone Production.” Apr. 2019.
- Riba, Na'ma. איך תיראה האבן הירושלמית בעוד מאה שנה?” עיצוב, הארץ, 11 (How will the Jerusalem stone Look Like in 100 years) June 2018, www.haaretz.co.il/gallery/design/.premium-MAGAZINE-1.6159682.