Historic lime-binders: An example of the 19th century Dutch military plain concrete

Before the general acceptance of Portland cement as the main binder for concrete in the late 19th century, other, locally available binders were occasionally used. In the case of the Netherlands, which did not produce Portland cement, traditional lime-based binders were not uncommon. With a strong tradition of trass production, trass-lime binders were used for hydraulic concrete structures as well. For Dutch military works such binders were commonly used for plain concrete structures in the middle and late 19th century, often in combination with crushed bricks as coarse aggregate. In this paper, the possibilities of the application of optical microscopy to characterise such concretes is discussed.