Additives in cement and plaster ensure strong, water-resistant materials, but they are often expensive and harmful to the environment. PhD candidate Annet Baken investigated whether more sustainable alternatives exist. Through experiments and X-ray measurements, she discovered how such substances influence the nanoscale crystal formation of building minerals, thereby slowing down the hardening process.

Cement paste contains superplasticisers such as polycarboxylates to slow down hardening, and plasterboard contains water-repellent additives. Such additives are often poorly biodegradable and can lead to eutrophication when they end up in the environment. They also cost the industry billions.

Over the past three years, materials scientist Annet Baken (see photo above) has been studying how portlandite (calcium hydroxide, a key mineral in cement) and gypsum crystallise when reacting with the commonly used additives peracetic acid (PAA) and STMP. Armed with this knowledge, chemical companies could select environmentally friendly additives more effectively, rather than continuing to test random alternatives.