UNIVERSITY OF APPLIED SCIENCES NUREMBERG GEORG SIMON OHM

Effects of fumed silica on material
engineering parameters of external
rendering, with special emphasis on thermal conductivity and compressive strength

A 5 vol.% addition of fumed silica is seen to reduce the thermal conductivity of a CS IV plinth render by nearly 29 %, from λ10, dry = 0.45 to 0.32 W/(m·K). At the same time, the compressive strength improved by 49 %, from 10.0 to 14.9 MPa. The higher the pore volume ratio, the more successfully the thermal conductivity can be reduced. The gain in compressive strength can be attributed to portlandite decomposition, i.e., to the pozzolanic reaction between the calcium hydroxide and the fumed silica.

1 Introduction and objectives

The main prerequisite for energy-efficient operation of residential and non-residential buildings is that they are appropriately insulated against heat loss. While modern, highly insulative wall building materials can always be used for new buildings, the walls of existing structures require a subsequent energy efficiency upgrade. The thermal resistance of the walls can be improved by installing (additional) interior or exterior thermal insulation and/or by applying plaster and render with superior thermal insulation properties. Highly insulative render contains a...

Related articles:

Issue 2018-9 UNIVERSITY OF APPLIED SCIENCES NUREMBERG GEORG SIMON OHM

Improving the thermal insulation properties of thin-bed mortar|Part II: Effects of selected admixtures and combinations thereof on material properties, in particular pore-size distribution, thermal conductivity and compressive strength

1 Introduction and objectives The main objective of the subject research work was to develop a new type of thin-bed mortar characterized by reduced thermal conductivity with no loss of compressive...

more
Issue 2018-6 University of applied sciences Nuremberg GEORG SIMON OHM

Improving the thermal insulation properties of thin-bed mortar Part I: Impact evaluations of various admixtures on material engineering parameters

1 Introduction Thin-bed cement mortar is often used for masoning up such precision-ground, monolithic wall-building materials as bricks, autoclaved aerated concrete units (Ytong), or building blocks...

more
Issue 2022-2

Strength and impermeability of cement-based materials containing nano silica-polymer composites

1 Introduction Concrete is the most widely used civil engineering material in the world. Over the years the output of concrete from China has made up more than half the world’s total output. Concrete...

more
Issue 2021-3 WUHAN UNIVERSITY OF SCIENCE AND TECHNOLOGY | WUHAN TEXTILE UNIVERSITY | WUHAN UNIVERSITY OF TECHNOLOGY

Mechanical properties and hydration characteristics of sulfoaluminate cement-based materials containing nano silica

1 Introduction Sulfoaluminate cement (SAC) has been regarded as a green and environment-friendly high-performance special cement due to its lower energy consumption and lower CO2 emissions when...

more
Issue 2021-3 YILDIZ TEKNIK UNIVERSITY | ISTANBUL UNIVERSITY-CERRAHPA?A | MALTEPE UNIVERSITY

Advances in physical and mechanical properties of wheat straw ash-substituted cement mortar

1 Introduction Globally, wheat seed is the main product derived from the wheat plant. According to the Supply and Demand Report of U.S. Wheat Associates, which was published on June 11th, 2020, 773...

more