• 1 The Congo Free State and king Leopold II’s gruesome “red rubber”-regime has attracted large attent (...)

1When on the 18th of October 1908, the Belgian parliament voted in favor of the Belgian takeover of the Congo Free State from the Belgian king Léopold II, this was far from a unanimous decision. The advocates of the reprise had held up prospects of great gain by referring to the enormous mineral wealth of the colony, whereas the adversaries acutely remarked that the colony would only remain profitable if Belgium would continue on the same plundering elan as their internationally condemned king.1 The reality check came quickly, when one of the strongest advocates, Jules Renkin, visited the Belgian Congo in his new role as the first minister of colonies. After a five-month journey through “his” colony, he realized that for the material realization of the colonial ambitions to be economically and practically feasible, a cheap, locally produced building material would be of quintessential importance. However, as the colonial presence was justified through the paternalistic image of “helping” the African inhabitants on their “path to modernity,” this colonial building material could not just be any of the existing local building materials, as these were publicly denounced for being non-durable, insalubre [unhygienic] or even puant [stinking]. Though seemingly a deadlock, the technocrats of the Belgian Congo remarkably quickly formulated an answer to this question: Concrete. Once a local cement plant would be established—which eventually only happened in 1921 after several failed attempts—concrete would be the deus-ex-machina that could resolve the apparent contradiction between the economic necessity to use local materials on the one hand and the cultural disdain towards local materials on the other. Though all of its components—apart from the reinforcement bars—could be locally sourced, the “magic” happened when in bringing these materials together, they still turned into the most “modern” material on the planet.

• 2 Daniel Headrick, The Tools of Empire: Technology and European Imperialism In the Nineteenth Centur (...)

3This importance of concrete for the colonial state was the starting premise of my PhD thesis. Hence, following Daniel Headrick’s seminal 1981 book—in which he argues that science and technology were the main weapons in Europe’s colonial dominance of the 19th and 20th century—, concrete is initially framed as a “tool of empire.”2 But in the two main parts of my work, I seek to nuance this reading. First, by questioning how far concrete and cement can be conceptualized as European materials, and second, by challenging the idea that the empire builders of the Belgian Congo indeed mastered this “tool.”

• 3 There is a substantial literature on the topic. See, among others : Cyrille Simonnet, Le Béton : h (...)

4The first part, entitled “Constructing Materials,” questions Europe’s centrality in the development of cement by looking at its Congolese biography. Today, cement’s history largely locates the invention of the material in 19th-century western Europe, with some prehistories going back to ancient Rome.3 Although I don’t want to question that several crucial moments in the history of the material should indeed be located there, this focus is still rather limiting: the cement invented in the 19th century is by no means the material we know today. Hence, any history of cement should go beyond such moments of invention and recognize production processes as an intrinsic part of the material’s history. Such attention to the production sites automatically brings another—much more global and diverse—history into focus. In the first part of the dissertation, I scrutinize this diversity by zooming in on the production of cement in Congo.

• 4 For a first discussion of this cement plant, see Robby Fivez, “The Rubble in the Jungle: A Fragmen (...)

5The first chapter looks “forward,” turning towards the production of cement in Congo’s first cement plant, the Cimenterie du Congo in Lukala.4 It is based on a significant number of archival files from the cement company, kept in the Belgian State Archives, as well as on the so-called Africa Archives in Brussels, which hold the papers of the former Ministry of Colonies and part of the collections of the former colonial administration in the Belgian Congo. Through three crucial episodes in the biography of Lukala cement, the first cement produced on and from Congolese soil, I disclose how a variety of local actants—including, for instance, the resisting geological layers, ambitious geologists, disgruntled laborers, colonial administrators, local land owners or the cement kiln—all had an enormous impact on this Lukala cement, which eventually reached strengths that were well-above the Belgian requirements for High-Resistance Portland Cement. It was only through all sorts of economic processes that the Lukala cement was eventually homogenized, turning it into a commodity that was highly similar to the cement imported from Belgium. Though today, with even more pronounced regulating processes, cement has become a universal commodity that is transported across the globe, this narrative shows how in the past the material had a remarkable material diversity. Congolese cement had only quite little to do with the types of cement that developed simultaneously in Europe, making this “global” material very much a local one.

• 5 See, among others, Sandra Harding (ed.), The Postcolonial Science and Technology Studies Reader, D (...)

7The first part of the PhD thesis thus critically examines the understanding of concrete as a “tool of empire,” by adding local nuances to the history of its most important component. By doing so, I also subscribe to the criticism of postcolonial science and technology studies that challenges European centrality in the development of science and technology at large, which is an implicit assumption of Headrick’s Tools of Empire approach.5 The second part of the PhD thesis, entitled “Building Ambitions,” starts from the same goal: to critically understand if concrete should indeed be considered a “tool of empire.” Here a close reading of three key construction sites challenges the extent to which the European empire builders effectively mastered this “tool.”

• 6 A source of crucial importance for this PhD thesis, and the second and third case study in particu (...)

8Not attempting exhaustivity in a study of such a ubiquitous material as concrete, but rather striving to provide in depth investigations, I decided to focus on three case studies, the choice of which was informed both by available source material and their relevance in an analysis of the development of concrete technology in Congo.6 All three cases chosen were key construction sites for Belgian colonial ambitions: (1) the new, state-of-the-art harbor of Ango-Ango (1925-1930) in the city of Matadi had to prevent a bottleneck in the logistical system of the colony’s extractive economy; (2) the CCC-building (1950), an office building that was to accommodate the headquarters of the building’s contractor, the Compagnie Congolaise de Construction, was one of the first “skyscrapers” in the colonial capital of Léopoldville (today Kinshasa) that had to send the unequivocal message to the world that the Belgian Congo had turned into a modern state; and (3) the Bata 300 factory in post-independence Kinshasa (1963-1966), designed as a new type of modular production plant for the famous Bata shoes, shows how Belgian contractors and engineers tried to reposition themselves in the radically different context of the newly independent state. Moreover, the three cases also correspond to some major technical innovations concrete underwent: (1) the harbour of Ango-Ango was an early example of reinforced concrete construction in the Belgian Congo; (2) in the CCC-building prestressed concrete was applied for the first time in a building in central Africa; and (3) in the case of the Bata 300 factory in Kinshasa, the standardization and mass-production of concrete elements was an attempt to industrialize construction and relieve on-site difficulties. Through this selection of case studies, I intended to gauge how these forms of concrete technology, that were only just introduced in Congo, were applied in a Congolese context. The close reading of the specific construction processes that resulted from this case-based approach, quickly revealed that building in concrete did not always go smoothly. On the contrary, the building sites were troubled by all sorts of incidents, accidents, and complications. The construction of the Ango-Ango harbour, discussed in Chapter 3, was perhaps the most spectacular in that sense. After building for five years and spending 40 million Francs, the plans for the concrete harbor were eventually abandoned in favour of a simple steel jetty. And while the CCC-building and the Bata 300 factory, the cases developed in Chapter 4 and Chapter 5, could at first sight be interpreted as a success, the close reading of these “successful” construction processes instead exposed how their execution was also far from flawless. Considering the errors made in both buildings, including enormous mistakes in the calculation of reinforcement steel, it is rather astonishing these buildings are still standing in Kinshasa today. This second part of my PhD thesis, quite literally consisting of chapters of accidents, again underlines how understanding concrete as a fully mastered “tool” was a far cry from reality—however keen the “concrete state” was to present it as such.