ABSTRACT The Jubilee Church in the south-eastern outskirts of Rome is one of the first buildings constructed with super white reinforced concrete with self-cleaning photocatalytic cement. However, 16 years after the opening of the building, the self-cleaning and colour-preserving properties arising from the titania particles (TiO2) within the concrete mix are not meeting the design requirements and the concrete is showing premature evidence of decay. While the form of the decay is affecting the appearance of the building and not its structural soundness, the ageing pattern of the building's components is resulting in a high maintenance cost, one not easily affordable within the ordinary budget supported by a small parish. This study comprises the first comprehensive step in understanding the causes of the accelerated ageing pattern of the concrete, highlighting methods to improve the long-term durability of the concrete and therefore reduce the cost of its maintenance. Moreover, this research offered the opportunity to test the durability and the effectiveness of the TiO2 in the real conditions on an actual building featuring non-standard geometries. The findings highlight how the ageing pattern directly connects with the geometry of the building and inadequate consideration of the local weathering at the design stage.

中文翻译：

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光催化混凝土的自清洁和保色效率：以罗马禧年教堂为例

摘要 位于罗马东南郊的禧年教堂是最早用超白钢筋混凝土和自洁光催化水泥建造的建筑之一。然而，在大楼启用 16 年后，混凝土混合物中二氧化钛颗粒 (TiO2) 产生的自清洁和保色性能不符合设计要求，混凝土出现过早腐烂迹象。虽然腐烂的形式会影响建筑物的外观而不是其结构的健全性，但建筑物部件的老化模式导致了高昂的维护成本，在一个小教区支持的普通预算内不容易负担得起。该研究包括了解混凝土加速老化模式的原因的第一个综合步骤，重点介绍提高混凝土长期耐久性并因此降低其维护成本的方法。此外，这项研究为在具有非标准几何形状的实际建筑物的实际条件下测试 TiO2 的耐用性和有效性提供了机会。研究结果强调了老化模式如何与建筑物的几何形状直接相关，以及在设计阶段对局部风化的考虑不足。这项研究为在具有非标准几何形状的实际建筑物的实际条件下测试 TiO2 的耐用性和有效性提供了机会。研究结果强调了老化模式如何与建筑物的几何形状直接相关，以及在设计阶段对局部风化的考虑不足。这项研究为在具有非标准几何形状的实际建筑物的实际条件下测试 TiO2 的耐用性和有效性提供了机会。研究结果强调了老化模式如何与建筑物的几何形状直接相关，以及在设计阶段对局部风化的考虑不足。