# Thermal Conductivity and Thermal Behavior of Mortar Containing Wood Shavings and Sawdust
## 2 Materials and Methods  
Cement used was CEM II/B-M (P-W-L) 42.5N (Lafarge, Greece) and crushed limestone aggregates with a 4.5 mm maximum size were used in all mixtures. Sieve analysis of limestone aggregates is shown in Figure 1. The bulk density of fine aggregates was 1730 \(\pm\) 40 kg/m\({}^{3}\). Wood shavings and wood sawdust used in this study were generated in a factory by mechanical processing of beech type of wood. In terms of fineness, the average grade of sawdust is 0.15-0.5 mm. Its sieve analysis is shown in Figure 1.  
Usually, the particle distribution of materials is estimated by sieve analysis. In the case of wood shavings, a question that could be emerged is which is the actual dimension that corresponds to the nominal sieve size and if a large proportion of shavings have a longer length that width, if this affects the critical dimension, as during sieve analysis a shaving could pass the sieve by its wight and not by its length. For this reason, all shavings having a length of more than 3 mm (actually able to be optically discriminated) were measured using a high-accuracy digital calliper. Two dimensions were measured on each shaving: length, which was taken to be the maximum dimension, and width, which was taken to be the dimension of the shaving on an axis perpendicular to the length. Results are shown in Figure 2. As it is shown, a portion of the wood shavings is longer than 5 mm, and due to their elongated shape--where length significantly exceeds width--the results of the sieve analysis may be misleading. Following on the same samples that were partly measured using a caliper, sieve analysis was performed on fine aggregates, and it is shown in Figure 1.  
Results of sieve analysis of wood shavings and fine limestone aggregates are shown in Figure 1. Bulk density of wood shavings was 67 \(\pm\) 2 kg/m\({}^{3}\) and bulk density of wood sawdust was 296 \(\pm\) 5 kg/m\({}^{3}\). The bulk density of wood shavings and sawdust was determined by measuring the mass of ten different samples, each occupying a fixed volume. Sika ViscoFlow superplasticizer was used in all mixes. Figure 1: Results of sieve analysis. Figure 2: Width versus length for wood shavings. All mix proportions are presented in Table 1. The proportioning of mortar mixtures was conducted with consideration of their prospective applications. One potential application could be as a lightweight, thermally insulating plaster, while another could be as mortar for restoration work. A lot of trial mixes were made in order to select the best mix proportions first for the reference mixes, so the workability remains at desired levels even after the replacement of conventional aggregates by wood shavings or sawdust. Because of the fact that these two act differently, two reference mixes were selected, one for the wood shavings replacement and one for the wood sawdust replacement. Then, 30, 50 and 70% of the amount of fine aggregates was removed and it was replaced by an amount of wood shavings that was decided to have an equal bulk volume as compared to the removed amount of fine aggregates. In this way, the critical parameter of water-to-cement ratio was kept constant (equal to 0.6), and at the same time, the workability of the mixture was acceptable. The same rationale was followed for mixes containing wood sawdust. For those calculations, the bulk density of shavings and sawdust was used because this is an easy way to measure their density. The actual density of solid wood material, in many cases, is too difficult to determine if it is an unknown material. Afterwards, when the density of fresh mortar was determined, all mix proportions were reviewed to calculate the corresponding values in kg/m\({}^{3}\). All information is given so that the experiments can be accurately reproduced and scientific progress is facilitated. For wood shavings, 30, 50 and 70% replacement were chosen as to cover a wide range of replacement. Sawdust has higher bulk density than shavings (296 kg/m\({}^{3}\) for sawdust instead of 67 kg/m\({}^{3}\) for shavings).