Development of microstructure of early cement paste (0–6 h) was investigated with 1H low-field NMR. It was found that T 2 (transverse relaxation time) distributions of fresh cement paste were bimodal and two peaks we...Development of microstructure of early cement paste (0–6 h) was investigated with 1H low-field NMR. It was found that T 2 (transverse relaxation time) distributions of fresh cement paste were bimodal and two peaks were ‘long component’ and ‘short component’. Separation degree of two peaks was a sign of exchange of water within flocculation and outside flocculation. Factors such as water cement ratio, specific surface area and dosage of superplasticizer had influences on the separation degree: the separation degree increased with the water cement ratio; the separation degree of cement paste prepared with cement with a high specific surface area was zero; dosage of superplasticizer will decrease separation degree. Results also suggested that T 2 distribution gradually moved to the left and T 2 of long component and initial fluidity were linearly correlated.展开更多
基金Funded by the National Natural Science Foundation of China(No.51178339)the National Basic Research Program(No.2009CB623104-5)
文摘Development of microstructure of early cement paste (0–6 h) was investigated with 1H low-field NMR. It was found that T 2 (transverse relaxation time) distributions of fresh cement paste were bimodal and two peaks were ‘long component’ and ‘short component’. Separation degree of two peaks was a sign of exchange of water within flocculation and outside flocculation. Factors such as water cement ratio, specific surface area and dosage of superplasticizer had influences on the separation degree: the separation degree increased with the water cement ratio; the separation degree of cement paste prepared with cement with a high specific surface area was zero; dosage of superplasticizer will decrease separation degree. Results also suggested that T 2 distribution gradually moved to the left and T 2 of long component and initial fluidity were linearly correlated.
